Merge branch 'master' into split_empty_delimiter_fix

import/n2mg_cypherl.sh

@@ -20,14 +20,18 @@ if [ ! -f "$INPUT" ]; then
 fi
 
 echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} BEGIN and COMMIT are required because variables share the same name (e.g. row)"
-echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} CONSTRAINTS are just skipped -> ${COLOR_RED}please create consraints manually if needed${COLOR_NULL}"
+echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} CONSTRAINTS are just skipped -> ${COLOR_RED}please create constraints manually if needed${COLOR_NULL}"
+
+echo 'CREATE INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' > "$OUTPUT"
 
 sed -e 's/^:begin/BEGIN/g; s/^BEGIN$/BEGIN;/g;' \
     -e 's/^:commit/COMMIT/g; s/^COMMIT$/COMMIT;/g;' \
     -e '/^CALL/d; /^SCHEMA AWAIT/d;' \
     -e 's/CREATE RANGE INDEX FOR (n:/CREATE INDEX ON :/g;' \
     -e 's/) ON (n./(/g;' \
-    -e '/^CREATE CONSTRAINT/d; /^DROP CONSTRAINT/d;' "$INPUT" > "$OUTPUT"
+    -e '/^CREATE CONSTRAINT/d; /^DROP CONSTRAINT/d;' "$INPUT" >> "$OUTPUT"
+
+echo 'DROP INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' >> "$OUTPUT"
 
 echo ""
 echo -e "${COLOR_GREEN}DONE!${COLOR_NULL} Please find Memgraph compatible cypherl|.cypher file under $OUTPUT"

import/n2mg_separate_files_cypherl.sh

@@ -0,0 +1,61 @@
+#!/bin/bash -e
+COLOR_ORANGE="\e[38;5;208m"
+COLOR_GREEN="\e[38;5;35m"
+COLOR_RED="\e[0;31m"
+COLOR_NULL="\e[0m"
+
+print_help() {
+    echo -e "${COLOR_ORANGE}HOW TO RUN:${COLOR_NULL} $0 input_file_schema_path input_file_nodes_path input_file_relationships_path input_file_cleanup_path output_file_path"
+    exit 1
+}
+
+if [ "$#" -ne 5 ]; then
+    print_help
+fi
+INPUT_SCHEMA="$1"
+INPUT_NODES="$2"
+INPUT_RELATIONSHIPS="$3"
+INPUT_CLEANUP="$4"
+OUTPUT="$5"
+
+if [ ! -f "$INPUT_SCHEMA" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_NODES" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_RELATIONSHIPS" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_CLEANUP" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} BEGIN and COMMIT are required because variables share the same name (e.g. row)"
+echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} CONSTRAINTS are just skipped -> ${COLOR_RED}please create constraints manually if needed${COLOR_NULL}"
+
+
+echo 'CREATE INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' > "$OUTPUT"
+
+sed -e 's/CREATE RANGE INDEX FOR (n:/CREATE INDEX ON :/g;' \
+    -e 's/) ON (n./(/g;' \
+    -e '/^CREATE CONSTRAINT/d' $INPUT_SCHEMA >> "$OUTPUT"
+
+cat "$INPUT_NODES" >> "$OUTPUT"
+cat "$INPUT_RELATIONSHIPS" >> "$OUTPUT"
+
+sed -e '/^DROP CONSTRAINT/d' "$INPUT_CLEANUP" >> "$OUTPUT"
+
+echo 'DROP INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' >> "$OUTPUT"
+
+echo ""
+echo -e "${COLOR_GREEN}DONE!${COLOR_NULL} Please find Memgraph compatible cypherl|.cypher file under $OUTPUT"
+echo ""
+echo "Please import data by executing => \`cat $OUTPUT | mgconsole\`"

import/n2mg_separate_files_cypherls.sh

@@ -0,0 +1,64 @@
+#!/bin/bash -e
+COLOR_ORANGE="\e[38;5;208m"
+COLOR_GREEN="\e[38;5;35m"
+COLOR_RED="\e[0;31m"
+COLOR_NULL="\e[0m"
+
+print_help() {
+    echo -e "${COLOR_ORANGE}HOW TO RUN:${COLOR_NULL} $0 input_file_schema_path input_file_nodes_path input_file_relationships_path input_file_cleanup_path output_file_schema_path output_file_nodes_path output_file_relationships_path output_file_cleanup_path"
+    exit 1
+}
+
+if [ "$#" -ne 8 ]; then
+    print_help
+fi
+INPUT_SCHEMA="$1"
+INPUT_NODES="$2"
+INPUT_RELATIONSHIPS="$3"
+INPUT_CLEANUP="$4"
+OUTPUT_SCHEMA="$5"
+OUTPUT_NODES="$6"
+OUTPUT_RELATIONSHIPS="$7"
+OUTPUT_CLEANUP="$8"
+
+if [ ! -f "$INPUT_SCHEMA" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_NODES" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_RELATIONSHIPS" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+if [ ! -f "$INPUT_CLEANUP" ]; then
+    echo -e "${COLOR_RED}ERROR:${COLOR_NULL} input_file_path is not a file!"
+    print_help
+fi
+
+echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} BEGIN and COMMIT are required because variables share the same name (e.g. row)"
+echo -e "${COLOR_ORANGE}NOTE:${COLOR_NULL} CONSTRAINTS are just skipped -> ${COLOR_RED}please create constraints manually if needed${COLOR_NULL}"
+
+
+echo 'CREATE INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' > "$OUTPUT_SCHEMA"
+
+sed -e 's/CREATE RANGE INDEX FOR (n:/CREATE INDEX ON :/g;' \
+    -e 's/) ON (n./(/g;' \
+    -e '/^CREATE CONSTRAINT/d' $INPUT_SCHEMA >> "$OUTPUT_SCHEMA"
+
+cat "$INPUT_NODES" > "$OUTPUT_NODES"
+cat "$INPUT_RELATIONSHIPS" > "$OUTPUT_RELATIONSHIPS"
+
+sed -e '/^DROP CONSTRAINT/d' "$INPUT_CLEANUP" >> "$OUTPUT_CLEANUP"
+
+echo 'DROP INDEX ON :`UNIQUE IMPORT LABEL`(`UNIQUE IMPORT ID`);' >> "$OUTPUT_CLEANUP"
+
+echo ""
+echo -e "${COLOR_GREEN}DONE!${COLOR_NULL} Please find Memgraph compatible cypherl|.cypher files under $OUTPUT_SCHEMA, $OUTPUT_NODES, $OUTPUT_RELATIONSHIPS and $OUTPUT_CLEANUP"
+echo ""
+echo "Please import data by executing => \`cat $OUTPUT_SCHEMA | mgconsole\`, \`cat $OUTPUT_NODES | mgconsole\`, \`cat $OUTPUT_RELATIONSHIPS | mgconsole\` and \`cat $OUTPUT_CLEANUP | mgconsole\`"

src/communication/result_stream_faker.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/coordination/CMakeLists.txt

@@ -23,6 +23,7 @@ target_sources(mg-coordination
         include/nuraft/coordinator_state_manager.hpp
 
         PRIVATE
+        coordinator_config.cpp
         coordinator_client.cpp
         coordinator_state.cpp
         coordinator_rpc.cpp

src/coordination/coordinator_client.cpp

@@ -135,8 +135,7 @@ auto CoordinatorClient::SendSwapMainUUIDRpc(utils::UUID const &uuid) const -> bo
 
 auto CoordinatorClient::SendUnregisterReplicaRpc(std::string_view instance_name) const -> bool {
   try {
-    auto stream{rpc_client_.Stream<UnregisterReplicaRpc>(
+    auto stream{rpc_client_.Stream<UnregisterReplicaRpc>(instance_name)};
-        std::string(instance_name))};  // TODO: (andi) Try to change to stream string_view and do just one copy later
     if (!stream.AwaitResponse().success) {
       spdlog::error("Failed to receive successful RPC response for unregistering replica!");
       return false;

src/coordination/coordinator_cluster_state.cpp

@@ -18,78 +18,87 @@
 
 namespace memgraph::coordination {
 
-using replication_coordination_glue::ReplicationRole;
+void to_json(nlohmann::json &j, InstanceState const &instance_state) {
+  j = nlohmann::json{{"config", instance_state.config}, {"status", instance_state.status}};
+}
 
-CoordinatorClusterState::CoordinatorClusterState(CoordinatorClusterState const &other)
+void from_json(nlohmann::json const &j, InstanceState &instance_state) {
-    : instance_roles_{other.instance_roles_} {}
+  j.at("config").get_to(instance_state.config);
+  j.at("status").get_to(instance_state.status);
+}
+
+CoordinatorClusterState::CoordinatorClusterState(std::map<std::string, InstanceState, std::less<>> instances)
+    : instances_{std::move(instances)} {}
+
+CoordinatorClusterState::CoordinatorClusterState(CoordinatorClusterState const &other) : instances_{other.instances_} {}
 
 CoordinatorClusterState &CoordinatorClusterState::operator=(CoordinatorClusterState const &other) {
   if (this == &other) {
     return *this;
   }
-  instance_roles_ = other.instance_roles_;
+  instances_ = other.instances_;
   return *this;
 }
 
 CoordinatorClusterState::CoordinatorClusterState(CoordinatorClusterState &&other) noexcept
-    : instance_roles_{std::move(other.instance_roles_)} {}
+    : instances_{std::move(other.instances_)} {}
 
 CoordinatorClusterState &CoordinatorClusterState::operator=(CoordinatorClusterState &&other) noexcept {
   if (this == &other) {
     return *this;
   }
-  instance_roles_ = std::move(other.instance_roles_);
+  instances_ = std::move(other.instances_);
   return *this;
 }
 
 auto CoordinatorClusterState::MainExists() const -> bool {
   auto lock = std::shared_lock{log_lock_};
-  return std::ranges::any_of(instance_roles_,
+  return std::ranges::any_of(instances_,
-                             [](auto const &entry) { return entry.second.role == ReplicationRole::MAIN; });
+                             [](auto const &entry) { return entry.second.status == ReplicationRole::MAIN; });
 }
 
 auto CoordinatorClusterState::IsMain(std::string_view instance_name) const -> bool {
   auto lock = std::shared_lock{log_lock_};
-  auto const it = instance_roles_.find(instance_name);
+  auto const it = instances_.find(instance_name);
-  return it != instance_roles_.end() && it->second.role == ReplicationRole::MAIN;
+  return it != instances_.end() && it->second.status == ReplicationRole::MAIN;
 }
 
 auto CoordinatorClusterState::IsReplica(std::string_view instance_name) const -> bool {
   auto lock = std::shared_lock{log_lock_};
-  auto const it = instance_roles_.find(instance_name);
+  auto const it = instances_.find(instance_name);
-  return it != instance_roles_.end() && it->second.role == ReplicationRole::REPLICA;
+  return it != instances_.end() && it->second.status == ReplicationRole::REPLICA;
 }
 
-auto CoordinatorClusterState::InsertInstance(std::string_view instance_name, ReplicationRole role) -> void {
+auto CoordinatorClusterState::InsertInstance(std::string instance_name, InstanceState instance_state) -> void {
-  auto lock = std::unique_lock{log_lock_};
+  auto lock = std::lock_guard{log_lock_};
-  instance_roles_[instance_name.data()].role = role;
+  instances_.insert_or_assign(std::move(instance_name), std::move(instance_state));
 }
 
 auto CoordinatorClusterState::DoAction(TRaftLog log_entry, RaftLogAction log_action) -> void {
-  auto lock = std::unique_lock{log_lock_};
+  auto lock = std::lock_guard{log_lock_};
   switch (log_action) {
     case RaftLogAction::REGISTER_REPLICATION_INSTANCE: {
       auto const &config = std::get<CoordinatorClientConfig>(log_entry);
-      instance_roles_[config.instance_name] = InstanceState{config, ReplicationRole::REPLICA};
+      instances_[config.instance_name] = InstanceState{config, ReplicationRole::REPLICA};
       break;
     }
     case RaftLogAction::UNREGISTER_REPLICATION_INSTANCE: {
       auto const instance_name = std::get<std::string>(log_entry);
-      instance_roles_.erase(instance_name);
+      instances_.erase(instance_name);
       break;
     }
     case RaftLogAction::SET_INSTANCE_AS_MAIN: {
       auto const instance_name = std::get<std::string>(log_entry);
-      auto it = instance_roles_.find(instance_name);
+      auto it = instances_.find(instance_name);
-      MG_ASSERT(it != instance_roles_.end(), "Instance does not exist as part of raft state!");
+      MG_ASSERT(it != instances_.end(), "Instance does not exist as part of raft state!");
-      it->second.role = ReplicationRole::MAIN;
+      it->second.status = ReplicationRole::MAIN;
       break;
     }
     case RaftLogAction::SET_INSTANCE_AS_REPLICA: {
       auto const instance_name = std::get<std::string>(log_entry);
-      auto it = instance_roles_.find(instance_name);
+      auto it = instances_.find(instance_name);
-      MG_ASSERT(it != instance_roles_.end(), "Instance does not exist as part of raft state!");
+      MG_ASSERT(it != instances_.end(), "Instance does not exist as part of raft state!");
-      it->second.role = ReplicationRole::REPLICA;
+      it->second.status = ReplicationRole::REPLICA;
       break;
     }
     case RaftLogAction::UPDATE_UUID: {
@@ -99,64 +108,36 @@ auto CoordinatorClusterState::DoAction(TRaftLog log_entry, RaftLogAction log_act
   }
 }
 
-// TODO: (andi) Improve based on Gareth's comments
 auto CoordinatorClusterState::Serialize(ptr<buffer> &data) -> void {
   auto lock = std::shared_lock{log_lock_};
-  auto const role_to_string = [](auto const &role) -> std::string_view {
-    switch (role) {
-      case ReplicationRole::MAIN:
-        return "main";
-      case ReplicationRole::REPLICA:
-        return "replica";
-    }
-  };
 
-  auto const entry_to_string = [&role_to_string](auto const &entry) {
+  auto const log = nlohmann::json(instances_).dump();
-    return fmt::format("{}_{}", entry.first, role_to_string(entry.second.role));
-  };
 
-  auto instances_str_view = instance_roles_ | ranges::views::transform(entry_to_string);
+  data = buffer::alloc(sizeof(uint32_t) + log.size());
-  uint32_t size =
-      std::accumulate(instances_str_view.begin(), instances_str_view.end(), 0,
-                      [](uint32_t acc, auto const &entry) { return acc + sizeof(uint32_t) + entry.size(); });
-
-  data = buffer::alloc(size);
   buffer_serializer bs(data);
-  std::for_each(instances_str_view.begin(), instances_str_view.end(), [&bs](auto const &entry) { bs.put_str(entry); });
+  bs.put_str(log);
 }
 
 auto CoordinatorClusterState::Deserialize(buffer &data) -> CoordinatorClusterState {
-  auto const str_to_role = [](auto const &str) -> ReplicationRole {
-    if (str == "main") {
-      return ReplicationRole::MAIN;
-    }
-    return ReplicationRole::REPLICA;
-  };
-
-  CoordinatorClusterState cluster_state;
   buffer_serializer bs(data);
-  while (bs.size() > 0) {
+  auto const j = nlohmann::json::parse(bs.get_str());
-    auto const entry = bs.get_str();
+  auto instances = j.get<std::map<std::string, InstanceState, std::less<>>>();
-    auto const first_dash = entry.find('_');
+
-    auto const instance_name = entry.substr(0, first_dash);
+  return CoordinatorClusterState{std::move(instances)};
-    auto const role_str = entry.substr(first_dash + 1);
-    cluster_state.InsertInstance(instance_name, str_to_role(role_str));
-  }
-  return cluster_state;
 }
 
 auto CoordinatorClusterState::GetInstances() const -> std::vector<InstanceState> {
   auto lock = std::shared_lock{log_lock_};
-  return instance_roles_ | ranges::views::values | ranges::to<std::vector<InstanceState>>;
+  return instances_ | ranges::views::values | ranges::to<std::vector<InstanceState>>;
 }
 
 auto CoordinatorClusterState::GetUUID() const -> utils::UUID { return uuid_; }
 
 auto CoordinatorClusterState::FindCurrentMainInstanceName() const -> std::optional<std::string> {
   auto lock = std::shared_lock{log_lock_};
-  auto const it = std::ranges::find_if(instance_roles_,
+  auto const it =
-                                       [](auto const &entry) { return entry.second.role == ReplicationRole::MAIN; });
+      std::ranges::find_if(instances_, [](auto const &entry) { return entry.second.status == ReplicationRole::MAIN; });
-  if (it == instance_roles_.end()) {
+  if (it == instances_.end()) {
     return {};
   }
   return it->first;

src/coordination/coordinator_config.cpp

@@ -0,0 +1,54 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#ifdef MG_ENTERPRISE
+
+#include "coordination/coordinator_config.hpp"
+
+namespace memgraph::coordination {
+
+void to_json(nlohmann::json &j, ReplClientInfo const &config) {
+  j = nlohmann::json{{"instance_name", config.instance_name},
+                     {"replication_mode", config.replication_mode},
+                     {"replication_ip_address", config.replication_ip_address},
+                     {"replication_port", config.replication_port}};
+}
+
+void from_json(nlohmann::json const &j, ReplClientInfo &config) {
+  config.instance_name = j.at("instance_name").get<std::string>();
+  config.replication_mode = j.at("replication_mode").get<replication_coordination_glue::ReplicationMode>();
+  config.replication_ip_address = j.at("replication_ip_address").get<std::string>();
+  config.replication_port = j.at("replication_port").get<uint16_t>();
+}
+
+void to_json(nlohmann::json &j, CoordinatorClientConfig const &config) {
+  j = nlohmann::json{{"instance_name", config.instance_name},
+                     {"ip_address", config.ip_address},
+                     {"port", config.port},
+                     {"instance_health_check_frequency_sec", config.instance_health_check_frequency_sec.count()},
+                     {"instance_down_timeout_sec", config.instance_down_timeout_sec.count()},
+                     {"instance_get_uuid_frequency_sec", config.instance_get_uuid_frequency_sec.count()},
+                     {"replication_client_info", config.replication_client_info}};
+}
+
+void from_json(nlohmann::json const &j, CoordinatorClientConfig &config) {
+  config.instance_name = j.at("instance_name").get<std::string>();
+  config.ip_address = j.at("ip_address").get<std::string>();
+  config.port = j.at("port").get<uint16_t>();
+  config.instance_health_check_frequency_sec =
+      std::chrono::seconds{j.at("instance_health_check_frequency_sec").get<int>()};
+  config.instance_down_timeout_sec = std::chrono::seconds{j.at("instance_down_timeout_sec").get<int>()};
+  config.instance_get_uuid_frequency_sec = std::chrono::seconds{j.at("instance_get_uuid_frequency_sec").get<int>()};
+  config.replication_client_info = j.at("replication_client_info").get<ReplClientInfo>();
+}
+
+}  // namespace memgraph::coordination
+#endif

src/coordination/coordinator_instance.cpp

@@ -36,31 +36,28 @@ CoordinatorInstance::CoordinatorInstance()
             spdlog::info("Leader changed, starting all replication instances!");
             auto const instances = raft_state_.GetInstances();
             auto replicas = instances | ranges::views::filter([](auto const &instance) {
-                              return instance.role == ReplicationRole::REPLICA;
+                              return instance.status == ReplicationRole::REPLICA;
                             });
 
             std::ranges::for_each(replicas, [this](auto &replica) {
-              spdlog::info("Starting replication instance {}", replica.config.instance_name);
+              spdlog::info("Started pinging replication instance {}", replica.config.instance_name);
               repl_instances_.emplace_back(this, replica.config, client_succ_cb_, client_fail_cb_,
                                            &CoordinatorInstance::ReplicaSuccessCallback,
                                            &CoordinatorInstance::ReplicaFailCallback);
             });
 
             auto main = instances | ranges::views::filter(
-                                        [](auto const &instance) { return instance.role == ReplicationRole::MAIN; });
+                                        [](auto const &instance) { return instance.status == ReplicationRole::MAIN; });
-
-            // TODO: (andi) Add support for this
-            // MG_ASSERT(std::ranges::distance(main) == 1, "There should be exactly one main instance");
 
             std::ranges::for_each(main, [this](auto &main_instance) {
-              spdlog::info("Starting main instance {}", main_instance.config.instance_name);
+              spdlog::info("Started pinging main instance {}", main_instance.config.instance_name);
               repl_instances_.emplace_back(this, main_instance.config, client_succ_cb_, client_fail_cb_,
                                            &CoordinatorInstance::MainSuccessCallback,
                                            &CoordinatorInstance::MainFailCallback);
             });
 
             std::ranges::for_each(repl_instances_, [this](auto &instance) {
-              instance.SetNewMainUUID(raft_state_.GetUUID());  // TODO: (andi) Rename
+              instance.SetNewMainUUID(raft_state_.GetUUID());
               instance.StartFrequentCheck();
             });
           },
@@ -69,13 +66,13 @@ CoordinatorInstance::CoordinatorInstance()
             repl_instances_.clear();
           })) {
   client_succ_cb_ = [](CoordinatorInstance *self, std::string_view repl_instance_name) -> void {
-    auto lock = std::unique_lock{self->coord_instance_lock_};
+    auto lock = std::lock_guard{self->coord_instance_lock_};
     auto &repl_instance = self->FindReplicationInstance(repl_instance_name);
     std::invoke(repl_instance.GetSuccessCallback(), self, repl_instance_name);
   };
 
   client_fail_cb_ = [](CoordinatorInstance *self, std::string_view repl_instance_name) -> void {
-    auto lock = std::unique_lock{self->coord_instance_lock_};
+    auto lock = std::lock_guard{self->coord_instance_lock_};
     auto &repl_instance = self->FindReplicationInstance(repl_instance_name);
     std::invoke(repl_instance.GetFailCallback(), self, repl_instance_name);
   };
@@ -98,10 +95,8 @@ auto CoordinatorInstance::ShowInstances() const -> std::vector<InstanceStatus> {
             .raft_socket_address = instance->get_endpoint(),
             .cluster_role = "coordinator",
             .health = "unknown"};  // TODO: (andi) Get this info from RAFT and test it or when we will move
-                                   // CoordinatorState to every instance, we can be smarter about this using our RPC.
   };
-
+  auto instances_status = utils::fmap(raft_state_.GetAllCoordinators(), coord_instance_to_status);
-  auto instances_status = utils::fmap(coord_instance_to_status, raft_state_.GetAllCoordinators());
 
   if (raft_state_.IsLeader()) {
     auto const stringify_repl_role = [this](ReplicationInstance const &instance) -> std::string {
@@ -127,14 +122,14 @@ auto CoordinatorInstance::ShowInstances() const -> std::vector<InstanceStatus> {
       std::ranges::transform(repl_instances_, std::back_inserter(instances_status), process_repl_instance_as_leader);
     }
   } else {
-    auto const stringify_repl_role = [](ReplicationRole role) -> std::string {
+    auto const stringify_inst_status = [](ReplicationRole status) -> std::string {
-      return role == ReplicationRole::MAIN ? "main" : "replica";
+      return status == ReplicationRole::MAIN ? "main" : "replica";
     };
 
     // TODO: (andi) Add capability that followers can also return socket addresses
-    auto process_repl_instance_as_follower = [&stringify_repl_role](auto const &instance) -> InstanceStatus {
+    auto process_repl_instance_as_follower = [&stringify_inst_status](auto const &instance) -> InstanceStatus {
       return {.instance_name = instance.config.instance_name,
-              .cluster_role = stringify_repl_role(instance.role),
+              .cluster_role = stringify_inst_status(instance.status),
               .health = "unknown"};
     };
 
@@ -319,17 +314,20 @@ auto CoordinatorInstance::RegisterReplicationInstance(CoordinatorClientConfig co
     return RegisterInstanceCoordinatorStatus::NOT_LEADER;
   }
 
+  auto const undo_action_ = [this]() { repl_instances_.pop_back(); };
+
   auto *new_instance = &repl_instances_.emplace_back(this, config, client_succ_cb_, client_fail_cb_,
                                                      &CoordinatorInstance::ReplicaSuccessCallback,
                                                      &CoordinatorInstance::ReplicaFailCallback);
 
   if (!new_instance->SendDemoteToReplicaRpc()) {
     spdlog::error("Failed to send demote to replica rpc for instance {}", config.instance_name);
-    repl_instances_.pop_back();
+    undo_action_();
     return RegisterInstanceCoordinatorStatus::RPC_FAILED;
   }
 
   if (!raft_state_.AppendRegisterReplicationInstanceLog(config)) {
+    undo_action_();
     return RegisterInstanceCoordinatorStatus::RAFT_LOG_ERROR;
   }
 
@@ -356,11 +354,11 @@ auto CoordinatorInstance::UnregisterReplicationInstance(std::string_view instanc
     return UnregisterInstanceCoordinatorStatus::NO_INSTANCE_WITH_NAME;
   }
 
-  // TODO: (andi) Change so that RaftLogState is the central place for asking who is main...
+  auto const is_main = [this](ReplicationInstance const &instance) {
+    return IsMain(instance.InstanceName()) && instance.GetMainUUID() == raft_state_.GetUUID() && instance.IsAlive();
+  };
 
-  auto const is_main = [this](ReplicationInstance const &instance) { return IsMain(instance.InstanceName()); };
+  if (is_main(*inst_to_remove)) {
-
-  if (is_main(*inst_to_remove) && inst_to_remove->IsAlive()) {
     return UnregisterInstanceCoordinatorStatus::IS_MAIN;
   }
 

src/coordination/coordinator_log_store.cpp

@@ -62,34 +62,33 @@ ptr<log_entry> CoordinatorLogStore::last_entry() const {
 
 uint64_t CoordinatorLogStore::append(ptr<log_entry> &entry) {
   ptr<log_entry> clone = MakeClone(entry);
-  uint64_t next_slot{0};
+
-  {
+  auto lock = std::lock_guard{logs_lock_};
-    auto lock = std::lock_guard{logs_lock_};
+  uint64_t next_slot = start_idx_ + logs_.size() - 1;
-    next_slot = start_idx_ + logs_.size() - 1;
+  logs_[next_slot] = clone;
-    logs_[next_slot] = clone;
+
-  }
   return next_slot;
 }
 
+// TODO: (andi) I think this is used for resolving conflicts inside NuRaft, check...
+// different compared to in_memory_log_store.cxx
 void CoordinatorLogStore::write_at(uint64_t index, ptr<log_entry> &entry) {
   ptr<log_entry> clone = MakeClone(entry);
 
   // Discard all logs equal to or greater than `index.
-  {
+  auto lock = std::lock_guard{logs_lock_};
-    auto lock = std::lock_guard{logs_lock_};
+  auto itr = logs_.lower_bound(index);
-    auto itr = logs_.lower_bound(index);
+  while (itr != logs_.end()) {
-    while (itr != logs_.end()) {
+    itr = logs_.erase(itr);
-      itr = logs_.erase(itr);
-    }
-    logs_[index] = clone;
   }
+  logs_[index] = clone;
 }
 
 ptr<std::vector<ptr<log_entry>>> CoordinatorLogStore::log_entries(uint64_t start, uint64_t end) {
   auto ret = cs_new<std::vector<ptr<log_entry>>>();
   ret->resize(end - start);
 
-  for (uint64_t i = start, curr_index = 0; i < end; ++i, ++curr_index) {
+  for (uint64_t i = start, curr_index = 0; i < end; i++, curr_index++) {
     ptr<log_entry> src = nullptr;
     {
       auto lock = std::lock_guard{logs_lock_};
@@ -105,21 +104,14 @@ ptr<std::vector<ptr<log_entry>>> CoordinatorLogStore::log_entries(uint64_t start
 }
 
 ptr<log_entry> CoordinatorLogStore::entry_at(uint64_t index) {
-  ptr<log_entry> src = nullptr;
+  auto lock = std::lock_guard{logs_lock_};
-  {
+  ptr<log_entry> src = FindOrDefault_(index);
-    auto lock = std::lock_guard{logs_lock_};
-    src = FindOrDefault_(index);
-  }
   return MakeClone(src);
 }
 
 uint64_t CoordinatorLogStore::term_at(uint64_t index) {
-  uint64_t term = 0;
+  auto lock = std::lock_guard{logs_lock_};
-  {
+  return FindOrDefault_(index)->get_term();
-    auto lock = std::lock_guard{logs_lock_};
-    term = FindOrDefault_(index)->get_term();
-  }
-  return term;
 }
 
 ptr<buffer> CoordinatorLogStore::pack(uint64_t index, int32 cnt) {

src/coordination/coordinator_state_machine.cpp

@@ -14,6 +14,10 @@
 #include "nuraft/coordinator_state_machine.hpp"
 #include "utils/logging.hpp"
 
+namespace {
+constexpr int MAX_SNAPSHOTS = 3;
+}  // namespace
+
 namespace memgraph::coordination {
 
 auto CoordinatorStateMachine::FindCurrentMainInstanceName() const -> std::optional<std::string> {
@@ -30,90 +34,83 @@ auto CoordinatorStateMachine::IsReplica(std::string_view instance_name) const ->
   return cluster_state_.IsReplica(instance_name);
 }
 
-auto CoordinatorStateMachine::CreateLog(std::string_view log) -> ptr<buffer> {
+auto CoordinatorStateMachine::CreateLog(nlohmann::json &&log) -> ptr<buffer> {
-  ptr<buffer> log_buf = buffer::alloc(sizeof(uint32_t) + log.size());
+  auto const log_dump = log.dump();
+  ptr<buffer> log_buf = buffer::alloc(sizeof(uint32_t) + log_dump.size());
   buffer_serializer bs(log_buf);
-  bs.put_str(log.data());
+  bs.put_str(log_dump);
   return log_buf;
 }
 
 auto CoordinatorStateMachine::SerializeRegisterInstance(CoordinatorClientConfig const &config) -> ptr<buffer> {
-  auto const str_log = fmt::format("{}*register", config.ToString());
+  return CreateLog({{"action", RaftLogAction::REGISTER_REPLICATION_INSTANCE}, {"info", config}});
-  return CreateLog(str_log);
 }
 
 auto CoordinatorStateMachine::SerializeUnregisterInstance(std::string_view instance_name) -> ptr<buffer> {
-  auto const str_log = fmt::format("{}*unregister", instance_name);
+  return CreateLog({{"action", RaftLogAction::UNREGISTER_REPLICATION_INSTANCE}, {"info", instance_name}});
-  return CreateLog(str_log);
 }
 
 auto CoordinatorStateMachine::SerializeSetInstanceAsMain(std::string_view instance_name) -> ptr<buffer> {
-  auto const str_log = fmt::format("{}*promote", instance_name);
+  return CreateLog({{"action", RaftLogAction::SET_INSTANCE_AS_MAIN}, {"info", instance_name}});
-  return CreateLog(str_log);
 }
 
 auto CoordinatorStateMachine::SerializeSetInstanceAsReplica(std::string_view instance_name) -> ptr<buffer> {
-  auto const str_log = fmt::format("{}*demote", instance_name);
+  return CreateLog({{"action", RaftLogAction::SET_INSTANCE_AS_REPLICA}, {"info", instance_name}});
-  return CreateLog(str_log);
 }
 
 auto CoordinatorStateMachine::SerializeUpdateUUID(utils::UUID const &uuid) -> ptr<buffer> {
-  auto const str_log = fmt::format("{}*update_uuid", nlohmann::json{{"uuid", uuid}}.dump());
+  return CreateLog({{"action", RaftLogAction::UPDATE_UUID}, {"info", uuid}});
-  return CreateLog(str_log);
 }
 
 auto CoordinatorStateMachine::DecodeLog(buffer &data) -> std::pair<TRaftLog, RaftLogAction> {
   buffer_serializer bs(data);
+  auto const json = nlohmann::json::parse(bs.get_str());
 
-  auto const log_str = bs.get_str();
+  auto const action = json["action"].get<RaftLogAction>();
-  auto const sep = log_str.find('*');
+  auto const &info = json["info"];
-  auto const action = log_str.substr(sep + 1);
-  auto const info = log_str.substr(0, sep);
 
-  if (action == "register") {
+  switch (action) {
-    return {CoordinatorClientConfig::FromString(info), RaftLogAction::REGISTER_REPLICATION_INSTANCE};
+    case RaftLogAction::REGISTER_REPLICATION_INSTANCE:
+      return {info.get<CoordinatorClientConfig>(), action};
+    case RaftLogAction::UPDATE_UUID:
+      return {info.get<utils::UUID>(), action};
+    case RaftLogAction::UNREGISTER_REPLICATION_INSTANCE:
+    case RaftLogAction::SET_INSTANCE_AS_MAIN:
+      [[fallthrough]];
+    case RaftLogAction::SET_INSTANCE_AS_REPLICA:
+      return {info.get<std::string>(), action};
   }
-  if (action == "unregister") {
-    return {info, RaftLogAction::UNREGISTER_REPLICATION_INSTANCE};
-  }
-  if (action == "promote") {
-    return {info, RaftLogAction::SET_INSTANCE_AS_MAIN};
-  }
-  if (action == "demote") {
-    return {info, RaftLogAction::SET_INSTANCE_AS_REPLICA};
-  }
-  if (action == "update_uuid") {
-    auto const json = nlohmann::json::parse(info);
-    return {json.at("uuid").get<utils::UUID>(), RaftLogAction::UPDATE_UUID};
-  }
-
   throw std::runtime_error("Unknown action");
 }
 
 auto CoordinatorStateMachine::pre_commit(ulong const /*log_idx*/, buffer & /*data*/) -> ptr<buffer> { return nullptr; }
 
 auto CoordinatorStateMachine::commit(ulong const log_idx, buffer &data) -> ptr<buffer> {
-  buffer_serializer bs(data);
+  spdlog::debug("Commit: log_idx={}, data.size()={}", log_idx, data.size());
-
   auto const [parsed_data, log_action] = DecodeLog(data);
   cluster_state_.DoAction(parsed_data, log_action);
-
   last_committed_idx_ = log_idx;
-  // TODO: (andi) Don't return nullptr
+
-  return nullptr;
+  // Return raft log number
+  ptr<buffer> ret = buffer::alloc(sizeof(log_idx));
+  buffer_serializer bs_ret(ret);
+  bs_ret.put_u64(log_idx);
+  return ret;
 }
 
 auto CoordinatorStateMachine::commit_config(ulong const log_idx, ptr<cluster_config> & /*new_conf*/) -> void {
   last_committed_idx_ = log_idx;
+  spdlog::debug("Commit config: log_idx={}", log_idx);
 }
 
 auto CoordinatorStateMachine::rollback(ulong const log_idx, buffer &data) -> void {
   // NOTE: Nothing since we don't do anything in pre_commit
+  spdlog::debug("Rollback: log_idx={}, data.size()={}", log_idx, data.size());
 }
 
 auto CoordinatorStateMachine::read_logical_snp_obj(snapshot &snapshot, void *& /*user_snp_ctx*/, ulong obj_id,
                                                    ptr<buffer> &data_out, bool &is_last_obj) -> int {
-  spdlog::info("read logical snapshot object, obj_id: {}", obj_id);
+  spdlog::debug("read logical snapshot object, obj_id: {}", obj_id);
 
   ptr<SnapshotCtx> ctx = nullptr;
   {
@@ -126,20 +123,33 @@ auto CoordinatorStateMachine::read_logical_snp_obj(snapshot &snapshot, void *& /
     }
     ctx = entry->second;
   }
-  ctx->cluster_state_.Serialize(data_out);
+
-  is_last_obj = true;
+  if (obj_id == 0) {
+    // Object ID == 0: first object, put dummy data.
+    data_out = buffer::alloc(sizeof(int32));
+    buffer_serializer bs(data_out);
+    bs.put_i32(0);
+    is_last_obj = false;
+  } else {
+    // Object ID > 0: second object, put actual value.
+    ctx->cluster_state_.Serialize(data_out);
+  }
+
   return 0;
 }
 
 auto CoordinatorStateMachine::save_logical_snp_obj(snapshot &snapshot, ulong &obj_id, buffer &data, bool is_first_obj,
                                                    bool is_last_obj) -> void {
-  spdlog::info("save logical snapshot object, obj_id: {}, is_first_obj: {}, is_last_obj: {}", obj_id, is_first_obj,
+  spdlog::debug("save logical snapshot object, obj_id: {}, is_first_obj: {}, is_last_obj: {}", obj_id, is_first_obj,
-               is_last_obj);
+                is_last_obj);
 
-  buffer_serializer bs(data);
+  if (obj_id == 0) {
-  auto cluster_state = CoordinatorClusterState::Deserialize(data);
+    ptr<buffer> snp_buf = snapshot.serialize();
+    auto ss = snapshot::deserialize(*snp_buf);
+    create_snapshot_internal(ss);
+  } else {
+    auto cluster_state = CoordinatorClusterState::Deserialize(data);
 
-  {
     auto ll = std::lock_guard{snapshots_lock_};
     auto entry = snapshots_.find(snapshot.get_last_log_idx());
     DMG_ASSERT(entry != snapshots_.end());
@@ -149,6 +159,7 @@ auto CoordinatorStateMachine::save_logical_snp_obj(snapshot &snapshot, ulong &ob
 
 auto CoordinatorStateMachine::apply_snapshot(snapshot &s) -> bool {
   auto ll = std::lock_guard{snapshots_lock_};
+  spdlog::debug("apply snapshot, last_log_idx: {}", s.get_last_log_idx());
 
   auto entry = snapshots_.find(s.get_last_log_idx());
   if (entry == snapshots_.end()) return false;
@@ -161,6 +172,7 @@ auto CoordinatorStateMachine::free_user_snp_ctx(void *&user_snp_ctx) -> void {}
 
 auto CoordinatorStateMachine::last_snapshot() -> ptr<snapshot> {
   auto ll = std::lock_guard{snapshots_lock_};
+  spdlog::debug("last_snapshot");
   auto entry = snapshots_.rbegin();
   if (entry == snapshots_.rend()) return nullptr;
 
@@ -171,6 +183,7 @@ auto CoordinatorStateMachine::last_snapshot() -> ptr<snapshot> {
 auto CoordinatorStateMachine::last_commit_index() -> ulong { return last_committed_idx_; }
 
 auto CoordinatorStateMachine::create_snapshot(snapshot &s, async_result<bool>::handler_type &when_done) -> void {
+  spdlog::debug("create_snapshot, last_log_idx: {}", s.get_last_log_idx());
   ptr<buffer> snp_buf = s.serialize();
   ptr<snapshot> ss = snapshot::deserialize(*snp_buf);
   create_snapshot_internal(ss);
@@ -182,11 +195,11 @@ auto CoordinatorStateMachine::create_snapshot(snapshot &s, async_result<bool>::h
 
 auto CoordinatorStateMachine::create_snapshot_internal(ptr<snapshot> snapshot) -> void {
   auto ll = std::lock_guard{snapshots_lock_};
+  spdlog::debug("create_snapshot_internal, last_log_idx: {}", snapshot->get_last_log_idx());
 
   auto ctx = cs_new<SnapshotCtx>(snapshot, cluster_state_);
   snapshots_[snapshot->get_last_log_idx()] = ctx;
 
-  constexpr int MAX_SNAPSHOTS = 3;
   while (snapshots_.size() > MAX_SNAPSHOTS) {
     snapshots_.erase(snapshots_.begin());
   }

src/coordination/include/coordination/coordinator_config.hpp

@@ -22,12 +22,12 @@
 #include <string>
 
 #include <fmt/format.h>
+#include "json/json.hpp"
 
 namespace memgraph::coordination {
 
 inline constexpr auto *kDefaultReplicationServerIp = "0.0.0.0";
 
-// TODO: (andi) JSON serialization for RAFT log.
 struct CoordinatorClientConfig {
   std::string instance_name;
   std::string ip_address;
@@ -43,28 +43,11 @@ struct CoordinatorClientConfig {
   }
 
   struct ReplicationClientInfo {
-    // TODO: (andi) Do we even need here instance_name for this struct?
     std::string instance_name;
     replication_coordination_glue::ReplicationMode replication_mode{};
     std::string replication_ip_address;
     uint16_t replication_port{};
 
-    auto ToString() const -> std::string {
-      return fmt::format("{}#{}#{}#{}", instance_name, replication_ip_address, replication_port,
-                         replication_coordination_glue::ReplicationModeToString(replication_mode));
-    }
-
-    // TODO: (andi) How can I make use of monadic parsers here?
-    static auto FromString(std::string_view log) -> ReplicationClientInfo {
-      ReplicationClientInfo replication_client_info;
-      auto splitted = utils::Split(log, "#");
-      replication_client_info.instance_name = splitted[0];
-      replication_client_info.replication_ip_address = splitted[1];
-      replication_client_info.replication_port = std::stoi(splitted[2]);
-      replication_client_info.replication_mode = replication_coordination_glue::ReplicationModeFromString(splitted[3]);
-      return replication_client_info;
-    }
-
     friend bool operator==(ReplicationClientInfo const &, ReplicationClientInfo const &) = default;
   };
 
@@ -79,25 +62,6 @@ struct CoordinatorClientConfig {
 
   std::optional<SSL> ssl;
 
-  auto ToString() const -> std::string {
-    return fmt::format("{}|{}|{}|{}|{}|{}|{}", instance_name, ip_address, port,
-                       instance_health_check_frequency_sec.count(), instance_down_timeout_sec.count(),
-                       instance_get_uuid_frequency_sec.count(), replication_client_info.ToString());
-  }
-
-  static auto FromString(std::string_view log) -> CoordinatorClientConfig {
-    CoordinatorClientConfig config;
-    auto splitted = utils::Split(log, "|");
-    config.instance_name = splitted[0];
-    config.ip_address = splitted[1];
-    config.port = std::stoi(splitted[2]);
-    config.instance_health_check_frequency_sec = std::chrono::seconds(std::stoi(splitted[3]));
-    config.instance_down_timeout_sec = std::chrono::seconds(std::stoi(splitted[4]));
-    config.instance_get_uuid_frequency_sec = std::chrono::seconds(std::stoi(splitted[5]));
-    config.replication_client_info = ReplicationClientInfo::FromString(splitted[6]);
-    return config;
-  }
-
   friend bool operator==(CoordinatorClientConfig const &, CoordinatorClientConfig const &) = default;
 };
 
@@ -119,5 +83,11 @@ struct CoordinatorServerConfig {
   friend bool operator==(CoordinatorServerConfig const &, CoordinatorServerConfig const &) = default;
 };
 
+void to_json(nlohmann::json &j, CoordinatorClientConfig const &config);
+void from_json(nlohmann::json const &j, CoordinatorClientConfig &config);
+
+void to_json(nlohmann::json &j, ReplClientInfo const &config);
+void from_json(nlohmann::json const &j, ReplClientInfo &config);
+
 }  // namespace memgraph::coordination
 #endif

src/coordination/include/coordination/coordinator_rpc.hpp

@@ -90,7 +90,7 @@ struct UnregisterReplicaReq {
   static void Load(UnregisterReplicaReq *self, memgraph::slk::Reader *reader);
   static void Save(UnregisterReplicaReq const &self, memgraph::slk::Builder *builder);
 
-  explicit UnregisterReplicaReq(std::string instance_name) : instance_name(std::move(instance_name)) {}
+  explicit UnregisterReplicaReq(std::string_view inst_name) : instance_name(inst_name) {}
 
   UnregisterReplicaReq() = default;
 

src/coordination/include/coordination/raft_state.hpp

@@ -14,6 +14,7 @@
 #ifdef MG_ENTERPRISE
 
 #include <flags/replication.hpp>
+#include "io/network/endpoint.hpp"
 #include "nuraft/coordinator_state_machine.hpp"
 #include "nuraft/coordinator_state_manager.hpp"
 
@@ -79,9 +80,8 @@ class RaftState {
 
  private:
   // TODO: (andi) I think variables below can be abstracted/clean them.
+  io::network::Endpoint raft_endpoint_;
   uint32_t raft_server_id_;
-  uint32_t raft_port_;
-  std::string raft_address_;
 
   ptr<CoordinatorStateMachine> state_machine_;
   ptr<CoordinatorStateManager> state_manager_;

src/coordination/include/nuraft/coordinator_cluster_state.hpp

@@ -21,6 +21,7 @@
 
 #include <libnuraft/nuraft.hxx>
 #include <range/v3/view.hpp>
+#include "json/json.hpp"
 
 #include <map>
 #include <numeric>
@@ -33,9 +34,16 @@ using replication_coordination_glue::ReplicationRole;
 
 struct InstanceState {
   CoordinatorClientConfig config;
-  ReplicationRole role;
+  ReplicationRole status;
+
+  friend auto operator==(InstanceState const &lhs, InstanceState const &rhs) -> bool {
+    return lhs.config == rhs.config && lhs.status == rhs.status;
+  }
 };
 
+void to_json(nlohmann::json &j, InstanceState const &instance_state);
+void from_json(nlohmann::json const &j, InstanceState &instance_state);
+
 using TRaftLog = std::variant<CoordinatorClientConfig, std::string, utils::UUID>;
 
 using nuraft::buffer;
@@ -45,6 +53,8 @@ using nuraft::ptr;
 class CoordinatorClusterState {
  public:
   CoordinatorClusterState() = default;
+  explicit CoordinatorClusterState(std::map<std::string, InstanceState, std::less<>> instances);
+
   CoordinatorClusterState(CoordinatorClusterState const &);
   CoordinatorClusterState &operator=(CoordinatorClusterState const &);
 
@@ -60,7 +70,7 @@ class CoordinatorClusterState {
 
   auto IsReplica(std::string_view instance_name) const -> bool;
 
-  auto InsertInstance(std::string_view instance_name, ReplicationRole role) -> void;
+  auto InsertInstance(std::string instance_name, InstanceState instance_state) -> void;
 
   auto DoAction(TRaftLog log_entry, RaftLogAction log_action) -> void;
 
@@ -73,7 +83,7 @@ class CoordinatorClusterState {
   auto GetUUID() const -> utils::UUID;
 
  private:
-  std::map<std::string, InstanceState, std::less<>> instance_roles_;
+  std::map<std::string, InstanceState, std::less<>> instances_{};
   utils::UUID uuid_{};
   mutable utils::ResourceLock log_lock_{};
 };

src/coordination/include/nuraft/coordinator_state_machine.hpp

@@ -47,7 +47,7 @@ class CoordinatorStateMachine : public state_machine {
   auto IsMain(std::string_view instance_name) const -> bool;
   auto IsReplica(std::string_view instance_name) const -> bool;
 
-  static auto CreateLog(std::string_view log) -> ptr<buffer>;
+  static auto CreateLog(nlohmann::json &&log) -> ptr<buffer>;
   static auto SerializeRegisterInstance(CoordinatorClientConfig const &config) -> ptr<buffer>;
   static auto SerializeUnregisterInstance(std::string_view instance_name) -> ptr<buffer>;
   static auto SerializeSetInstanceAsMain(std::string_view instance_name) -> ptr<buffer>;
@@ -95,12 +95,8 @@ class CoordinatorStateMachine : public state_machine {
   auto create_snapshot_internal(ptr<snapshot> snapshot) -> void;
 
   CoordinatorClusterState cluster_state_;
-
-  // mutable utils::RWLock lock{utils::RWLock::Priority::READ};
-
   std::atomic<uint64_t> last_committed_idx_{0};
 
-  // TODO: (andi) Maybe not needed, remove it
   std::map<uint64_t, ptr<SnapshotCtx>> snapshots_;
   std::mutex snapshots_lock_;
 

src/coordination/include/nuraft/raft_log_action.hpp

@@ -18,6 +18,8 @@
 #include <cstdint>
 #include <string>
 
+#include "json/json.hpp"
+
 namespace memgraph::coordination {
 
 enum class RaftLogAction : uint8_t {
@@ -28,26 +30,13 @@ enum class RaftLogAction : uint8_t {
   UPDATE_UUID
 };
 
-inline auto ParseRaftLogAction(std::string_view action) -> RaftLogAction {
+NLOHMANN_JSON_SERIALIZE_ENUM(RaftLogAction, {
-  if (action == "register") {
+                                                {RaftLogAction::REGISTER_REPLICATION_INSTANCE, "register"},
-    return RaftLogAction::REGISTER_REPLICATION_INSTANCE;
+                                                {RaftLogAction::UNREGISTER_REPLICATION_INSTANCE, "unregister"},
-  }
+                                                {RaftLogAction::SET_INSTANCE_AS_MAIN, "promote"},
-  if (action == "unregister") {
+                                                {RaftLogAction::SET_INSTANCE_AS_REPLICA, "demote"},
-    return RaftLogAction::UNREGISTER_REPLICATION_INSTANCE;
+                                                {RaftLogAction::UPDATE_UUID, "update_uuid"},
-  }
+                                            })
-  if (action == "promote") {
-    return RaftLogAction::SET_INSTANCE_AS_MAIN;
-  }
-  if (action == "demote") {
-    return RaftLogAction::SET_INSTANCE_AS_REPLICA;
-  }
-
-  if (action == "update_uuid") {
-    return RaftLogAction::UPDATE_UUID;
-  }
-
-  throw InvalidRaftLogActionException("Invalid Raft log action: {}.", action);
-}
 
 }  // namespace memgraph::coordination
 #endif

src/coordination/raft_state.cpp

@@ -10,11 +10,11 @@
 // licenses/APL.txt.
 
 #ifdef MG_ENTERPRISE
-
+#include <chrono>
-#include "coordination/raft_state.hpp"
 
 #include "coordination/coordinator_config.hpp"
 #include "coordination/coordinator_exceptions.hpp"
+#include "coordination/raft_state.hpp"
 #include "utils/counter.hpp"
 
 namespace memgraph::coordination {
@@ -32,31 +32,35 @@ using raft_result = cmd_result<ptr<buffer>>;
 
 RaftState::RaftState(BecomeLeaderCb become_leader_cb, BecomeFollowerCb become_follower_cb, uint32_t raft_server_id,
                      uint32_t raft_port, std::string raft_address)
-    : raft_server_id_(raft_server_id),
+    : raft_endpoint_(raft_address, raft_port),
-      raft_port_(raft_port),
+      raft_server_id_(raft_server_id),
-      raft_address_(std::move(raft_address)),
       state_machine_(cs_new<CoordinatorStateMachine>()),
-      state_manager_(
+      state_manager_(cs_new<CoordinatorStateManager>(raft_server_id_, raft_endpoint_.SocketAddress())),
-          cs_new<CoordinatorStateManager>(raft_server_id_, raft_address_ + ":" + std::to_string(raft_port_))),
       logger_(nullptr),
       become_leader_cb_(std::move(become_leader_cb)),
       become_follower_cb_(std::move(become_follower_cb)) {}
 
 auto RaftState::InitRaftServer() -> void {
   asio_service::options asio_opts;
-  asio_opts.thread_pool_size_ = 1;  // TODO: (andi) Improve this
+  asio_opts.thread_pool_size_ = 1;
 
   raft_params params;
   params.heart_beat_interval_ = 100;
   params.election_timeout_lower_bound_ = 200;
   params.election_timeout_upper_bound_ = 400;
-  // 5 logs are preserved before the last snapshot
   params.reserved_log_items_ = 5;
-  // Create snapshot for every 5 log appends
   params.snapshot_distance_ = 5;
   params.client_req_timeout_ = 3000;
   params.return_method_ = raft_params::blocking;
 
+  // If the leader doesn't receive any response from quorum nodes
+  // in 200ms, it will step down.
+  // This allows us to achieve strong consistency even if network partition
+  // happens between the current leader and followers.
+  // The value must be <= election_timeout_lower_bound_ so that cluster can never
+  // have multiple leaders.
+  params.leadership_expiry_ = 200;
+
   raft_server::init_options init_opts;
   init_opts.raft_callback_ = [this](cb_func::Type event_type, cb_func::Param *param) -> nuraft::CbReturnCode {
     if (event_type == cb_func::BecomeLeader) {
@@ -71,11 +75,11 @@ auto RaftState::InitRaftServer() -> void {
 
   raft_launcher launcher;
 
-  raft_server_ = launcher.init(state_machine_, state_manager_, logger_, static_cast<int>(raft_port_), asio_opts, params,
+  raft_server_ =
-                               init_opts);
+      launcher.init(state_machine_, state_manager_, logger_, raft_endpoint_.port, asio_opts, params, init_opts);
 
   if (!raft_server_) {
-    throw RaftServerStartException("Failed to launch raft server on {}:{}", raft_address_, raft_port_);
+    throw RaftServerStartException("Failed to launch raft server on {}", raft_endpoint_.SocketAddress());
   }
 
   auto maybe_stop = utils::ResettableCounter<20>();
@@ -86,7 +90,7 @@ auto RaftState::InitRaftServer() -> void {
     std::this_thread::sleep_for(std::chrono::milliseconds(250));
   } while (!maybe_stop());
 
-  throw RaftServerStartException("Failed to initialize raft server on {}:{}", raft_address_, raft_port_);
+  throw RaftServerStartException("Failed to initialize raft server on {}", raft_endpoint_.SocketAddress());
 }
 
 auto RaftState::MakeRaftState(BecomeLeaderCb &&become_leader_cb, BecomeFollowerCb &&become_follower_cb) -> RaftState {
@@ -102,18 +106,45 @@ auto RaftState::MakeRaftState(BecomeLeaderCb &&become_leader_cb, BecomeFollowerC
 
 RaftState::~RaftState() { launcher_.shutdown(); }
 
-auto RaftState::InstanceName() const -> std::string { return "coordinator_" + std::to_string(raft_server_id_); }
+auto RaftState::InstanceName() const -> std::string {
+  return fmt::format("coordinator_{}", std::to_string(raft_server_id_));
+}
 
-auto RaftState::RaftSocketAddress() const -> std::string { return raft_address_ + ":" + std::to_string(raft_port_); }
+auto RaftState::RaftSocketAddress() const -> std::string { return raft_endpoint_.SocketAddress(); }
 
 auto RaftState::AddCoordinatorInstance(uint32_t raft_server_id, uint32_t raft_port, std::string_view raft_address)
     -> void {
   auto const endpoint = fmt::format("{}:{}", raft_address, raft_port);
   srv_config const srv_config_to_add(static_cast<int>(raft_server_id), endpoint);
-  if (!raft_server_->add_srv(srv_config_to_add)->get_accepted()) {
+
-    throw RaftAddServerException("Failed to add server {} to the cluster", endpoint);
+  auto cmd_result = raft_server_->add_srv(srv_config_to_add);
+
+  if (cmd_result->get_result_code() == nuraft::cmd_result_code::OK) {
+    spdlog::info("Request to add server {} to the cluster accepted", endpoint);
+  } else {
+    throw RaftAddServerException("Failed to accept request to add server {} to the cluster with error code {}",
+                                 endpoint, cmd_result->get_result_code());
+  }
+
+  // Waiting for server to join
+  constexpr int max_tries{10};
+  auto maybe_stop = utils::ResettableCounter<max_tries>();
+  constexpr int waiting_period{200};
+  bool added{false};
+  while (!maybe_stop()) {
+    std::this_thread::sleep_for(std::chrono::milliseconds(waiting_period));
+    const auto server_config = raft_server_->get_srv_config(static_cast<nuraft::int32>(raft_server_id));
+    if (server_config) {
+      spdlog::trace("Server with id {} added to cluster", raft_server_id);
+      added = true;
+      break;
+    }
+  }
+
+  if (!added) {
+    throw RaftAddServerException("Failed to add server {} to the cluster in {}ms", endpoint,
+                                 max_tries * waiting_period);
   }
-  spdlog::info("Request to add server {} to the cluster accepted", endpoint);
 }
 
 auto RaftState::GetAllCoordinators() const -> std::vector<ptr<srv_config>> {

src/dbms/database_handler.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/dbms/inmemory/replication_handlers.cpp

@@ -118,9 +118,14 @@ void InMemoryReplicationHandlers::Register(dbms::DbmsHandler *dbms_handler, repl
       });
   server.rpc_server_.Register<replication_coordination_glue::SwapMainUUIDRpc>(
       [&data, dbms_handler](auto *req_reader, auto *res_builder) {
-        spdlog::debug("Received SwapMainUUIDHandler");
+        spdlog::debug("Received SwapMainUUIDRpc");
         InMemoryReplicationHandlers::SwapMainUUIDHandler(dbms_handler, data, req_reader, res_builder);
       });
+  server.rpc_server_.Register<storage::replication::ForceResetStorageRpc>(
+      [&data, dbms_handler](auto *req_reader, auto *res_builder) {
+        spdlog::debug("Received ForceResetStorageRpc");
+        InMemoryReplicationHandlers::ForceResetStorageHandler(dbms_handler, data.uuid_, req_reader, res_builder);
+      });
 }
 
 void InMemoryReplicationHandlers::SwapMainUUIDHandler(dbms::DbmsHandler *dbms_handler,
@@ -329,6 +334,78 @@ void InMemoryReplicationHandlers::SnapshotHandler(dbms::DbmsHandler *dbms_handle
   spdlog::debug("Replication recovery from snapshot finished!");
 }
 
+void InMemoryReplicationHandlers::ForceResetStorageHandler(dbms::DbmsHandler *dbms_handler,
+                                                           const std::optional<utils::UUID> &current_main_uuid,
+                                                           slk::Reader *req_reader, slk::Builder *res_builder) {
+  storage::replication::ForceResetStorageReq req;
+  slk::Load(&req, req_reader);
+  auto db_acc = GetDatabaseAccessor(dbms_handler, req.db_uuid);
+  if (!db_acc) {
+    storage::replication::ForceResetStorageRes res{false, 0};
+    slk::Save(res, res_builder);
+    return;
+  }
+  if (!current_main_uuid.has_value() || req.main_uuid != current_main_uuid) [[unlikely]] {
+    LogWrongMain(current_main_uuid, req.main_uuid, storage::replication::SnapshotReq::kType.name);
+    storage::replication::ForceResetStorageRes res{false, 0};
+    slk::Save(res, res_builder);
+    return;
+  }
+
+  storage::replication::Decoder decoder(req_reader);
+
+  auto *storage = static_cast<storage::InMemoryStorage *>(db_acc->get()->storage());
+
+  auto storage_guard = std::unique_lock{storage->main_lock_};
+
+  // Clear the database
+  storage->vertices_.clear();
+  storage->edges_.clear();
+  storage->commit_log_.reset();
+  storage->commit_log_.emplace();
+
+  storage->constraints_.existence_constraints_ = std::make_unique<storage::ExistenceConstraints>();
+  storage->constraints_.unique_constraints_ = std::make_unique<storage::InMemoryUniqueConstraints>();
+  storage->indices_.label_index_ = std::make_unique<storage::InMemoryLabelIndex>();
+  storage->indices_.label_property_index_ = std::make_unique<storage::InMemoryLabelPropertyIndex>();
+
+  // Fine since we will force push when reading from WAL just random epoch with 0 timestamp, as it should be if it
+  // acted as MAIN before
+  storage->repl_storage_state_.epoch_.SetEpoch(std::string(utils::UUID{}));
+  storage->repl_storage_state_.last_commit_timestamp_ = 0;
+
+  storage->repl_storage_state_.history.clear();
+  storage->vertex_id_ = 0;
+  storage->edge_id_ = 0;
+  storage->timestamp_ = storage::kTimestampInitialId;
+
+  storage->CollectGarbage<true>(std::move(storage_guard), false);
+  storage->vertices_.run_gc();
+  storage->edges_.run_gc();
+
+  storage::replication::ForceResetStorageRes res{true, storage->repl_storage_state_.last_commit_timestamp_.load()};
+  slk::Save(res, res_builder);
+
+  spdlog::trace("Deleting old snapshot files.");
+  // Delete other durability files
+  auto snapshot_files = storage::durability::GetSnapshotFiles(storage->recovery_.snapshot_directory_, storage->uuid_);
+  for (const auto &[path, uuid, _] : snapshot_files) {
+    spdlog::trace("Deleting snapshot file {}", path);
+    storage->file_retainer_.DeleteFile(path);
+  }
+
+  spdlog::trace("Deleting old WAL files.");
+  auto wal_files = storage::durability::GetWalFiles(storage->recovery_.wal_directory_, storage->uuid_);
+  if (wal_files) {
+    for (const auto &wal_file : *wal_files) {
+      spdlog::trace("Deleting WAL file {}", wal_file.path);
+      storage->file_retainer_.DeleteFile(wal_file.path);
+    }
+
+    storage->wal_file_.reset();
+  }
+}
+
 void InMemoryReplicationHandlers::WalFilesHandler(dbms::DbmsHandler *dbms_handler,
                                                   const std::optional<utils::UUID> &current_main_uuid,
                                                   slk::Reader *req_reader, slk::Builder *res_builder) {
@@ -763,6 +840,20 @@ uint64_t InMemoryReplicationHandlers::ReadAndApplyDelta(storage::InMemoryStorage
         transaction->DeleteLabelPropertyIndexStats(storage->NameToLabel(info.label));
         break;
       }
+      case WalDeltaData::Type::EDGE_INDEX_CREATE: {
+        spdlog::trace("       Create edge index on :{}", delta.operation_edge_type.edge_type);
+        auto *transaction = get_transaction(timestamp, kUniqueAccess);
+        if (transaction->CreateIndex(storage->NameToEdgeType(delta.operation_label.label)).HasError())
+          throw utils::BasicException("Invalid transaction! Please raise an issue, {}:{}", __FILE__, __LINE__);
+        break;
+      }
+      case WalDeltaData::Type::EDGE_INDEX_DROP: {
+        spdlog::trace("       Drop edge index on :{}", delta.operation_edge_type.edge_type);
+        auto *transaction = get_transaction(timestamp, kUniqueAccess);
+        if (transaction->DropIndex(storage->NameToEdgeType(delta.operation_label.label)).HasError())
+          throw utils::BasicException("Invalid transaction! Please raise an issue, {}:{}", __FILE__, __LINE__);
+        break;
+      }
       case WalDeltaData::Type::EXISTENCE_CONSTRAINT_CREATE: {
         spdlog::trace("       Create existence constraint on :{} ({})", delta.operation_label_property.label,
                       delta.operation_label_property.property);

src/dbms/inmemory/replication_handlers.hpp

@@ -48,6 +48,9 @@ class InMemoryReplicationHandlers {
 
   static void SwapMainUUIDHandler(dbms::DbmsHandler *dbms_handler, replication::RoleReplicaData &role_replica_data,
                                   slk::Reader *req_reader, slk::Builder *res_builder);
+  static void ForceResetStorageHandler(dbms::DbmsHandler *dbms_handler,
+                                       const std::optional<utils::UUID> &current_main_uuid, slk::Reader *req_reader,
+                                       slk::Builder *res_builder);
 
   static void LoadWal(storage::InMemoryStorage *storage, storage::replication::Decoder *decoder);
 

src/glue/communication.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/io/network/endpoint.cpp

@@ -22,113 +22,15 @@
 #include "utils/message.hpp"
 #include "utils/string.hpp"
 
+namespace {
+constexpr std::string_view delimiter = ":";
+}  // namespace
+
 namespace memgraph::io::network {
 
-Endpoint::IpFamily Endpoint::GetIpFamily(std::string_view address) {
+// NOLINTNEXTLINE
-  in_addr addr4;
+Endpoint::Endpoint(needs_resolving_t, std::string hostname, uint16_t port)
-  in6_addr addr6;
+    : address(std::move(hostname)), port(port), family{GetIpFamily(address)} {}
-  int ipv4_result = inet_pton(AF_INET, address.data(), &addr4);
-  int ipv6_result = inet_pton(AF_INET6, address.data(), &addr6);
-  if (ipv4_result == 1) {
-    return IpFamily::IP4;
-  }
-  if (ipv6_result == 1) {
-    return IpFamily::IP6;
-  }
-  return IpFamily::NONE;
-}
-
-std::optional<std::pair<std::string, uint16_t>> Endpoint::ParseSocketOrIpAddress(
-    std::string_view address, const std::optional<uint16_t> default_port) {
-  /// expected address format:
-  ///   - "ip_address:port_number"
-  ///   - "ip_address"
-  /// We parse the address first. If it's an IP address, a default port must
-  // be given, or we return nullopt. If it's a socket address, we try to parse
-  // it into an ip address and a port number; even if a default port is given,
-  // it won't be used, as we expect that it is given in the address string.
-  const std::string delimiter = ":";
-  std::string ip_address;
-
-  std::vector<std::string> parts = utils::Split(address, delimiter);
-  if (parts.size() == 1) {
-    if (default_port) {
-      if (GetIpFamily(address) == IpFamily::NONE) {
-        return std::nullopt;
-      }
-      return std::pair{std::string(address), *default_port};  // TODO: (andi) Optimize throughout the code
-    }
-  } else if (parts.size() == 2) {
-    ip_address = std::move(parts[0]);
-    if (GetIpFamily(ip_address) == IpFamily::NONE) {
-      return std::nullopt;
-    }
-    int64_t int_port{0};
-    try {
-      int_port = utils::ParseInt(parts[1]);
-    } catch (utils::BasicException &e) {
-      spdlog::error(utils::MessageWithLink("Invalid port number {}.", parts[1], "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-    if (int_port < 0) {
-      spdlog::error(utils::MessageWithLink("Invalid port number {}. The port number must be a positive integer.",
-                                           int_port, "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-    if (int_port > std::numeric_limits<uint16_t>::max()) {
-      spdlog::error(utils::MessageWithLink("Invalid port number. The port number exceedes the maximum possible size.",
-                                           "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-
-    return std::pair{ip_address, static_cast<uint16_t>(int_port)};
-  }
-
-  return std::nullopt;
-}
-
-std::optional<std::pair<std::string, uint16_t>> Endpoint::ParseHostname(
-    std::string_view address, const std::optional<uint16_t> default_port = {}) {
-  const std::string delimiter = ":";
-  std::string ip_address;
-  std::vector<std::string> parts = utils::Split(address, delimiter);
-  if (parts.size() == 1) {
-    if (default_port) {
-      if (!IsResolvableAddress(address, *default_port)) {
-        return std::nullopt;
-      }
-      return std::pair{std::string(address), *default_port};  // TODO: (andi) Optimize throughout the code
-    }
-  } else if (parts.size() == 2) {
-    int64_t int_port{0};
-    auto hostname = std::move(parts[0]);
-    try {
-      int_port = utils::ParseInt(parts[1]);
-    } catch (utils::BasicException &e) {
-      spdlog::error(utils::MessageWithLink("Invalid port number {}.", parts[1], "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-    if (int_port < 0) {
-      spdlog::error(utils::MessageWithLink("Invalid port number {}. The port number must be a positive integer.",
-                                           int_port, "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-    if (int_port > std::numeric_limits<uint16_t>::max()) {
-      spdlog::error(utils::MessageWithLink("Invalid port number. The port number exceedes the maximum possible size.",
-                                           "https://memgr.ph/ports"));
-      return std::nullopt;
-    }
-    if (IsResolvableAddress(hostname, static_cast<uint16_t>(int_port))) {
-      return std::pair{hostname, static_cast<u_int16_t>(int_port)};
-    }
-  }
-  return std::nullopt;
-}
-
-std::string Endpoint::SocketAddress() const {
-  auto ip_address = address.empty() ? "EMPTY" : address;
-  return ip_address + ":" + std::to_string(port);
-}
 
 Endpoint::Endpoint(std::string ip_address, uint16_t port) : address(std::move(ip_address)), port(port) {
   IpFamily ip_family = GetIpFamily(address);
@@ -138,9 +40,23 @@ Endpoint::Endpoint(std::string ip_address, uint16_t port) : address(std::move(ip
   family = ip_family;
 }
 
-// NOLINTNEXTLINE
+std::string Endpoint::SocketAddress() const { return fmt::format("{}:{}", address, port); }
-Endpoint::Endpoint(needs_resolving_t, std::string hostname, uint16_t port)
+
-    : address(std::move(hostname)), port(port), family{GetIpFamily(address)} {}
+Endpoint::IpFamily Endpoint::GetIpFamily(std::string_view address) {
+  // Ensure null-terminated
+  auto const tmp = std::string(address);
+  in_addr addr4;
+  in6_addr addr6;
+  int ipv4_result = inet_pton(AF_INET, tmp.c_str(), &addr4);
+  int ipv6_result = inet_pton(AF_INET6, tmp.c_str(), &addr6);
+  if (ipv4_result == 1) {
+    return IpFamily::IP4;
+  }
+  if (ipv6_result == 1) {
+    return IpFamily::IP6;
+  }
+  return IpFamily::NONE;
+}
 
 std::ostream &operator<<(std::ostream &os, const Endpoint &endpoint) {
   // no need to cover the IpFamily::NONE case, as you can't even construct an
@@ -153,6 +69,7 @@ std::ostream &operator<<(std::ostream &os, const Endpoint &endpoint) {
   return os << endpoint.address << ":" << endpoint.port;
 }
 
+// NOTE: Intentional copy to ensure null-terminated string
 bool Endpoint::IsResolvableAddress(std::string_view address, uint16_t port) {
   addrinfo hints{
       .ai_flags = AI_PASSIVE,
@@ -160,28 +77,65 @@ bool Endpoint::IsResolvableAddress(std::string_view address, uint16_t port) {
       .ai_socktype = SOCK_STREAM  // TCP socket
   };
   addrinfo *info = nullptr;
-  auto status = getaddrinfo(address.data(), std::to_string(port).c_str(), &hints, &info);
+  auto status = getaddrinfo(std::string(address).c_str(), std::to_string(port).c_str(), &hints, &info);
   if (info) freeaddrinfo(info);
   return status == 0;
 }
 
-std::optional<std::pair<std::string, uint16_t>> Endpoint::ParseSocketOrAddress(
+std::optional<ParsedAddress> Endpoint::ParseSocketOrAddress(std::string_view address,
-    std::string_view address, const std::optional<uint16_t> default_port) {
+                                                            std::optional<uint16_t> default_port) {
-  const std::string delimiter = ":";
+  auto const parts = utils::SplitView(address, delimiter);
-  std::vector<std::string> parts = utils::Split(address, delimiter);
+
-  if (parts.size() == 1) {
+  if (parts.size() > 2) {
-    if (GetIpFamily(address) == IpFamily::NONE) {
+    return std::nullopt;
-      return ParseHostname(address, default_port);
-    }
-    return ParseSocketOrIpAddress(address, default_port);
   }
-  if (parts.size() == 2) {
+
-    if (GetIpFamily(parts[0]) == IpFamily::NONE) {
+  auto const port = [default_port, &parts]() -> std::optional<uint16_t> {
-      return ParseHostname(address, default_port);
+    if (parts.size() == 2) {
+      return static_cast<uint16_t>(utils::ParseInt(parts[1]));
     }
-    return ParseSocketOrIpAddress(address, default_port);
+    return default_port;
+  }();
+
+  if (!ValidatePort(port)) {
+    return std::nullopt;
   }
-  return std::nullopt;
+
+  auto const addr = [address, &parts]() {
+    if (parts.size() == 2) {
+      return parts[0];
+    }
+    return address;
+  }();
+
+  if (GetIpFamily(addr) == IpFamily::NONE) {
+    if (IsResolvableAddress(addr, *port)) {  // NOLINT
+      return std::pair{addr, *port};         // NOLINT
+    }
+    return std::nullopt;
+  }
+
+  return std::pair{addr, *port};  // NOLINT
+}
+
+auto Endpoint::ValidatePort(std::optional<uint16_t> port) -> bool {
+  if (!port) {
+    return false;
+  }
+
+  if (port < 0) {
+    spdlog::error(utils::MessageWithLink("Invalid port number {}. The port number must be a positive integer.", *port,
+                                         "https://memgr.ph/ports"));
+    return false;
+  }
+
+  if (port > std::numeric_limits<uint16_t>::max()) {
+    spdlog::error(utils::MessageWithLink("Invalid port number. The port number exceedes the maximum possible size.",
+                                         "https://memgr.ph/ports"));
+    return false;
+  }
+
+  return true;
 }
 
 }  // namespace memgraph::io::network

src/io/network/endpoint.hpp

@@ -19,11 +19,8 @@
 
 namespace memgraph::io::network {
 
-/**
+using ParsedAddress = std::pair<std::string_view, uint16_t>;
- * This class represents a network endpoint that is used in Socket.
+
- * It is used when connecting to an address and to get the current
- * connection address.
- */
 struct Endpoint {
   static const struct needs_resolving_t {
   } needs_resolving;
@@ -31,59 +28,35 @@ struct Endpoint {
   Endpoint() = default;
   Endpoint(std::string ip_address, uint16_t port);
   Endpoint(needs_resolving_t, std::string hostname, uint16_t port);
+
   Endpoint(Endpoint const &) = default;
   Endpoint(Endpoint &&) noexcept = default;
+
   Endpoint &operator=(Endpoint const &) = default;
   Endpoint &operator=(Endpoint &&) noexcept = default;
+
   ~Endpoint() = default;
 
   enum class IpFamily : std::uint8_t { NONE, IP4, IP6 };
 
-  std::string SocketAddress() const;
+  static std::optional<ParsedAddress> ParseSocketOrAddress(std::string_view address,
+                                                           std::optional<uint16_t> default_port = {});
 
-  bool operator==(const Endpoint &other) const = default;
+  std::string SocketAddress() const;
-  friend std::ostream &operator<<(std::ostream &os, const Endpoint &endpoint);
 
   std::string address;
   uint16_t port{0};
   IpFamily family{IpFamily::NONE};
 
-  static std::optional<std::pair<std::string, uint16_t>> ParseSocketOrAddress(
+  bool operator==(const Endpoint &other) const = default;
-      std::string_view address, std::optional<uint16_t> default_port = {});
+  friend std::ostream &operator<<(std::ostream &os, const Endpoint &endpoint);
-
-  /**
-   * Tries to parse the given string as either a socket address or ip address.
-   * Expected address format:
-   *   - "ip_address:port_number"
-   *   - "ip_address"
-   * We parse the address first. If it's an IP address, a default port must
-   * be given, or we return nullopt. If it's a socket address, we try to parse
-   * it into an ip address and a port number; even if a default port is given,
-   * it won't be used, as we expect that it is given in the address string.
-   */
-  static std::optional<std::pair<std::string, uint16_t>> ParseSocketOrIpAddress(
-      std::string_view address, std::optional<uint16_t> default_port = {});
-
-  /**
-   * Tries to parse given string as either socket address or hostname.
-   * Expected address format:
-   *    - "hostname:port_number"
-   *    - "hostname"
-   * After we parse hostname and port we try to resolve the hostname into an ip_address.
-   */
-  static std::optional<std::pair<std::string, uint16_t>> ParseHostname(std::string_view address,
-                                                                       std::optional<uint16_t> default_port);
 
+ private:
   static IpFamily GetIpFamily(std::string_view address);
 
   static bool IsResolvableAddress(std::string_view address, uint16_t port);
 
-  /**
+  static auto ValidatePort(std::optional<uint16_t> port) -> bool;
-   * Tries to resolve hostname to its corresponding IP address.
-   * Given a DNS hostname, this function performs resolution and returns
-   * the IP address associated with the hostname.
-   */
-  static std::string ResolveHostnameIntoIpAddress(const std::string &address, uint16_t port);
 };
 
 }  // namespace memgraph::io::network

src/query/db_accessor.hpp

@@ -371,6 +371,62 @@ class VerticesIterable final {
   }
 };
 
+class EdgesIterable final {
+  std::variant<storage::EdgesIterable, std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                                          utils::Allocator<EdgeAccessor>> *>
+      iterable_;
+
+ public:
+  class Iterator final {
+    std::variant<storage::EdgesIterable::Iterator,
+                 std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                    utils::Allocator<EdgeAccessor>>::iterator>
+        it_;
+
+   public:
+    explicit Iterator(storage::EdgesIterable::Iterator it) : it_(std::move(it)) {}
+    explicit Iterator(std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                         utils::Allocator<EdgeAccessor>>::iterator it)
+        : it_(it) {}
+
+    EdgeAccessor operator*() const {
+      return std::visit([](auto &it_) { return EdgeAccessor(*it_); }, it_);
+    }
+
+    Iterator &operator++() {
+      std::visit([](auto &it_) { ++it_; }, it_);
+      return *this;
+    }
+
+    bool operator==(const Iterator &other) const { return it_ == other.it_; }
+
+    bool operator!=(const Iterator &other) const { return !(other == *this); }
+  };
+
+  explicit EdgesIterable(storage::EdgesIterable iterable) : iterable_(std::move(iterable)) {}
+  explicit EdgesIterable(std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                            utils::Allocator<EdgeAccessor>> *edges)
+      : iterable_(edges) {}
+
+  Iterator begin() {
+    return std::visit(
+        memgraph::utils::Overloaded{
+            [](storage::EdgesIterable &iterable_) { return Iterator(iterable_.begin()); },
+            [](std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                  utils::Allocator<EdgeAccessor>> *iterable_) { return Iterator(iterable_->begin()); }},
+        iterable_);
+  }
+
+  Iterator end() {
+    return std::visit(
+        memgraph::utils::Overloaded{
+            [](storage::EdgesIterable &iterable_) { return Iterator(iterable_.end()); },
+            [](std::unordered_set<EdgeAccessor, std::hash<EdgeAccessor>, std::equal_to<void>,
+                                  utils::Allocator<EdgeAccessor>> *iterable_) { return Iterator(iterable_->end()); }},
+        iterable_);
+  }
+};
+
 class DbAccessor final {
   storage::Storage::Accessor *accessor_;
 
@@ -416,6 +472,10 @@ class DbAccessor final {
     return VerticesIterable(accessor_->Vertices(label, property, lower, upper, view));
   }
 
+  EdgesIterable Edges(storage::View view, storage::EdgeTypeId edge_type) {
+    return EdgesIterable(accessor_->Edges(edge_type, view));
+  }
+
   VertexAccessor InsertVertex() { return VertexAccessor(accessor_->CreateVertex()); }
 
   storage::Result<EdgeAccessor> InsertEdge(VertexAccessor *from, VertexAccessor *to,
@@ -572,6 +632,8 @@ class DbAccessor final {
     return accessor_->LabelPropertyIndexExists(label, prop);
   }
 
+  bool EdgeTypeIndexExists(storage::EdgeTypeId edge_type) const { return accessor_->EdgeTypeIndexExists(edge_type); }
+
   std::optional<storage::LabelIndexStats> GetIndexStats(const storage::LabelId &label) const {
     return accessor_->GetIndexStats(label);
   }
@@ -638,6 +700,10 @@ class DbAccessor final {
     return accessor_->CreateIndex(label, property);
   }
 
+  utils::BasicResult<storage::StorageIndexDefinitionError, void> CreateIndex(storage::EdgeTypeId edge_type) {
+    return accessor_->CreateIndex(edge_type);
+  }
+
   utils::BasicResult<storage::StorageIndexDefinitionError, void> DropIndex(storage::LabelId label) {
     return accessor_->DropIndex(label);
   }
@@ -647,6 +713,10 @@ class DbAccessor final {
     return accessor_->DropIndex(label, property);
   }
 
+  utils::BasicResult<storage::StorageIndexDefinitionError, void> DropIndex(storage::EdgeTypeId edge_type) {
+    return accessor_->DropIndex(edge_type);
+  }
+
   utils::BasicResult<storage::StorageExistenceConstraintDefinitionError, void> CreateExistenceConstraint(
       storage::LabelId label, storage::PropertyId property) {
     return accessor_->CreateExistenceConstraint(label, property);

src/query/dump.cpp

@@ -242,6 +242,10 @@ void DumpLabelIndex(std::ostream *os, query::DbAccessor *dba, const storage::Lab
   *os << "CREATE INDEX ON :" << EscapeName(dba->LabelToName(label)) << ";";
 }
 
+void DumpEdgeTypeIndex(std::ostream *os, query::DbAccessor *dba, const storage::EdgeTypeId edge_type) {
+  *os << "CREATE EDGE INDEX ON :" << EscapeName(dba->EdgeTypeToName(edge_type)) << ";";
+}
+
 void DumpLabelPropertyIndex(std::ostream *os, query::DbAccessor *dba, storage::LabelId label,
                             storage::PropertyId property) {
   *os << "CREATE INDEX ON :" << EscapeName(dba->LabelToName(label)) << "(" << EscapeName(dba->PropertyToName(property))
@@ -297,7 +301,9 @@ PullPlanDump::PullPlanDump(DbAccessor *dba, dbms::DatabaseAccess db_acc)
                    // Internal index cleanup
                    CreateInternalIndexCleanupPullChunk(),
                    // Dump all triggers
-                   CreateTriggersPullChunk()} {}
+                   CreateTriggersPullChunk(),
+                   // Dump all edge-type indices
+                   CreateEdgeTypeIndicesPullChunk()} {}
 
 bool PullPlanDump::Pull(AnyStream *stream, std::optional<int> n) {
   // Iterate all functions that stream some results.
@@ -352,6 +358,33 @@ PullPlanDump::PullChunk PullPlanDump::CreateLabelIndicesPullChunk() {
   };
 }
 
+PullPlanDump::PullChunk PullPlanDump::CreateEdgeTypeIndicesPullChunk() {
+  // Dump all label indices
+  return [this, global_index = 0U](AnyStream *stream, std::optional<int> n) mutable -> std::optional<size_t> {
+    // Delay the construction of indices vectors
+    if (!indices_info_) {
+      indices_info_.emplace(dba_->ListAllIndices());
+    }
+    const auto &edge_type = indices_info_->edge_type;
+
+    size_t local_counter = 0;
+    while (global_index < edge_type.size() && (!n || local_counter < *n)) {
+      std::ostringstream os;
+      DumpEdgeTypeIndex(&os, dba_, edge_type[global_index]);
+      stream->Result({TypedValue(os.str())});
+
+      ++global_index;
+      ++local_counter;
+    }
+
+    if (global_index == edge_type.size()) {
+      return local_counter;
+    }
+
+    return std::nullopt;
+  };
+}
+
 PullPlanDump::PullChunk PullPlanDump::CreateLabelPropertyIndicesPullChunk() {
   return [this, global_index = 0U](AnyStream *stream, std::optional<int> n) mutable -> std::optional<size_t> {
     // Delay the construction of indices vectors

src/query/dump.hpp

@@ -63,5 +63,6 @@ struct PullPlanDump {
   PullChunk CreateDropInternalIndexPullChunk();
   PullChunk CreateInternalIndexCleanupPullChunk();
   PullChunk CreateTriggersPullChunk();
+  PullChunk CreateEdgeTypeIndicesPullChunk();
 };
 }  // namespace memgraph::query

src/query/frontend/ast/ast.cpp

@@ -186,6 +186,9 @@ constexpr utils::TypeInfo query::ProfileQuery::kType{utils::TypeId::AST_PROFILE_
 
 constexpr utils::TypeInfo query::IndexQuery::kType{utils::TypeId::AST_INDEX_QUERY, "IndexQuery", &query::Query::kType};
 
+constexpr utils::TypeInfo query::EdgeIndexQuery::kType{utils::TypeId::AST_EDGE_INDEX_QUERY, "EdgeIndexQuery",
+                                                       &query::Query::kType};
+
 constexpr utils::TypeInfo query::Create::kType{utils::TypeId::AST_CREATE, "Create", &query::Clause::kType};
 
 constexpr utils::TypeInfo query::CallProcedure::kType{utils::TypeId::AST_CALL_PROCEDURE, "CallProcedure",

src/query/frontend/ast/ast.hpp

@@ -21,6 +21,7 @@
 #include "query/interpret/awesome_memgraph_functions.hpp"
 #include "query/typed_value.hpp"
 #include "storage/v2/property_value.hpp"
+#include "utils/exceptions.hpp"
 #include "utils/typeinfo.hpp"
 
 namespace memgraph::query {
@@ -2223,6 +2224,34 @@ class IndexQuery : public memgraph::query::Query {
   friend class AstStorage;
 };
 
+class EdgeIndexQuery : public memgraph::query::Query {
+ public:
+  static const utils::TypeInfo kType;
+  const utils::TypeInfo &GetTypeInfo() const override { return kType; }
+
+  enum class Action { CREATE, DROP };
+
+  EdgeIndexQuery() = default;
+
+  DEFVISITABLE(QueryVisitor<void>);
+
+  memgraph::query::EdgeIndexQuery::Action action_;
+  memgraph::query::EdgeTypeIx edge_type_;
+
+  EdgeIndexQuery *Clone(AstStorage *storage) const override {
+    EdgeIndexQuery *object = storage->Create<EdgeIndexQuery>();
+    object->action_ = action_;
+    object->edge_type_ = storage->GetEdgeTypeIx(edge_type_.name);
+    return object;
+  }
+
+ protected:
+  EdgeIndexQuery(Action action, EdgeTypeIx edge_type) : action_(action), edge_type_(edge_type) {}
+
+ private:
+  friend class AstStorage;
+};
+
 class Create : public memgraph::query::Clause {
  public:
   static const utils::TypeInfo kType;
@@ -3586,7 +3615,7 @@ class PatternComprehension : public memgraph::query::Expression {
   bool Accept(HierarchicalTreeVisitor &visitor) override {
     if (visitor.PreVisit(*this)) {
       if (variable_) {
-        variable_->Accept(visitor);
+        throw utils::NotYetImplemented("Variable in pattern comprehension.");
       }
       pattern_->Accept(visitor);
       if (filter_) {
@@ -3615,7 +3644,8 @@ class PatternComprehension : public memgraph::query::Expression {
   int32_t symbol_pos_{-1};
 
   PatternComprehension *Clone(AstStorage *storage) const override {
-    PatternComprehension *object = storage->Create<PatternComprehension>();
+    auto *object = storage->Create<PatternComprehension>();
+    object->variable_ = variable_ ? variable_->Clone(storage) : nullptr;
     object->pattern_ = pattern_ ? pattern_->Clone(storage) : nullptr;
     object->filter_ = filter_ ? filter_->Clone(storage) : nullptr;
     object->resultExpr_ = resultExpr_ ? resultExpr_->Clone(storage) : nullptr;
@@ -3625,7 +3655,8 @@ class PatternComprehension : public memgraph::query::Expression {
   }
 
  protected:
-  PatternComprehension(Identifier *variable, Pattern *pattern) : variable_(variable), pattern_(pattern) {}
+  PatternComprehension(Identifier *variable, Pattern *pattern, Where *filter, Expression *resultExpr)
+      : variable_(variable), pattern_(pattern), filter_(filter), resultExpr_(resultExpr) {}
 
  private:
   friend class AstStorage;

src/query/frontend/ast/ast_visitor.hpp

@@ -82,6 +82,7 @@ class AuthQuery;
 class ExplainQuery;
 class ProfileQuery;
 class IndexQuery;
+class EdgeIndexQuery;
 class DatabaseInfoQuery;
 class SystemInfoQuery;
 class ConstraintQuery;
@@ -143,11 +144,11 @@ class ExpressionVisitor
 
 template <class TResult>
 class QueryVisitor
-    : public utils::Visitor<TResult, CypherQuery, ExplainQuery, ProfileQuery, IndexQuery, AuthQuery, DatabaseInfoQuery,
+    : public utils::Visitor<TResult, CypherQuery, ExplainQuery, ProfileQuery, IndexQuery, EdgeIndexQuery, AuthQuery,
-                            SystemInfoQuery, ConstraintQuery, DumpQuery, ReplicationQuery, LockPathQuery,
+                            DatabaseInfoQuery, SystemInfoQuery, ConstraintQuery, DumpQuery, ReplicationQuery,
-                            FreeMemoryQuery, TriggerQuery, IsolationLevelQuery, CreateSnapshotQuery, StreamQuery,
+                            LockPathQuery, FreeMemoryQuery, TriggerQuery, IsolationLevelQuery, CreateSnapshotQuery,
-                            SettingQuery, VersionQuery, ShowConfigQuery, TransactionQueueQuery, StorageModeQuery,
+                            StreamQuery, SettingQuery, VersionQuery, ShowConfigQuery, TransactionQueueQuery,
-                            AnalyzeGraphQuery, MultiDatabaseQuery, ShowDatabasesQuery, EdgeImportModeQuery,
+                            StorageModeQuery, AnalyzeGraphQuery, MultiDatabaseQuery, ShowDatabasesQuery,
-                            CoordinatorQuery> {};
+                            EdgeImportModeQuery, CoordinatorQuery> {};
 
 }  // namespace memgraph::query

src/query/frontend/ast/cypher_main_visitor.cpp

@@ -265,6 +265,27 @@ antlrcpp::Any CypherMainVisitor::visitDropIndex(MemgraphCypher::DropIndexContext
   return index_query;
 }
 
+antlrcpp::Any CypherMainVisitor::visitEdgeIndexQuery(MemgraphCypher::EdgeIndexQueryContext *ctx) {
+  MG_ASSERT(ctx->children.size() == 1, "EdgeIndexQuery should have exactly one child!");
+  auto *index_query = std::any_cast<EdgeIndexQuery *>(ctx->children[0]->accept(this));
+  query_ = index_query;
+  return index_query;
+}
+
+antlrcpp::Any CypherMainVisitor::visitCreateEdgeIndex(MemgraphCypher::CreateEdgeIndexContext *ctx) {
+  auto *index_query = storage_->Create<EdgeIndexQuery>();
+  index_query->action_ = EdgeIndexQuery::Action::CREATE;
+  index_query->edge_type_ = AddEdgeType(std::any_cast<std::string>(ctx->labelName()->accept(this)));
+  return index_query;
+}
+
+antlrcpp::Any CypherMainVisitor::visitDropEdgeIndex(MemgraphCypher::DropEdgeIndexContext *ctx) {
+  auto *index_query = storage_->Create<EdgeIndexQuery>();
+  index_query->action_ = EdgeIndexQuery::Action::DROP;
+  index_query->edge_type_ = AddEdgeType(std::any_cast<std::string>(ctx->labelName()->accept(this)));
+  return index_query;
+}
+
 antlrcpp::Any CypherMainVisitor::visitAuthQuery(MemgraphCypher::AuthQueryContext *ctx) {
   MG_ASSERT(ctx->children.size() == 1, "AuthQuery should have exactly one child!");
   auto *auth_query = std::any_cast<AuthQuery *>(ctx->children[0]->accept(this));

src/query/frontend/ast/cypher_main_visitor.hpp

@@ -148,6 +148,11 @@ class CypherMainVisitor : public antlropencypher::MemgraphCypherBaseVisitor {
    */
   antlrcpp::Any visitIndexQuery(MemgraphCypher::IndexQueryContext *ctx) override;
 
+  /**
+   * @return IndexQuery*
+   */
+  antlrcpp::Any visitEdgeIndexQuery(MemgraphCypher::EdgeIndexQueryContext *ctx) override;
+
   /**
    * @return ExplainQuery*
    */
@@ -499,6 +504,16 @@ class CypherMainVisitor : public antlropencypher::MemgraphCypherBaseVisitor {
    */
   antlrcpp::Any visitDropIndex(MemgraphCypher::DropIndexContext *ctx) override;
 
+  /**
+   * @return EdgeIndexQuery*
+   */
+  antlrcpp::Any visitCreateEdgeIndex(MemgraphCypher::CreateEdgeIndexContext *ctx) override;
+
+  /**
+   * @return DropEdgeIndex*
+   */
+  antlrcpp::Any visitDropEdgeIndex(MemgraphCypher::DropEdgeIndexContext *ctx) override;
+
   /**
    * @return AuthQuery*
    */

src/query/frontend/opencypher/grammar/MemgraphCypher.g4

@@ -133,6 +133,7 @@ symbolicName : UnescapedSymbolicName
 
 query : cypherQuery
       | indexQuery
+      | edgeIndexQuery
       | explainQuery
       | profileQuery
       | databaseInfoQuery
@@ -527,3 +528,9 @@ showDatabase : SHOW DATABASE ;
 showDatabases : SHOW DATABASES ;
 
 edgeImportModeQuery : EDGE IMPORT MODE ( ACTIVE | INACTIVE ) ;
+
+createEdgeIndex : CREATE EDGE INDEX ON ':' labelName ;
+
+dropEdgeIndex : DROP EDGE INDEX ON ':' labelName ;
+
+edgeIndexQuery : createEdgeIndex | dropEdgeIndex ;

src/query/frontend/semantic/required_privileges.cpp

@@ -27,6 +27,8 @@ class PrivilegeExtractor : public QueryVisitor<void>, public HierarchicalTreeVis
 
   void Visit(IndexQuery & /*unused*/) override { AddPrivilege(AuthQuery::Privilege::INDEX); }
 
+  void Visit(EdgeIndexQuery & /*unused*/) override { AddPrivilege(AuthQuery::Privilege::INDEX); }
+
   void Visit(AnalyzeGraphQuery & /*unused*/) override { AddPrivilege(AuthQuery::Privilege::INDEX); }
 
   void Visit(AuthQuery & /*unused*/) override { AddPrivilege(AuthQuery::Privilege::AUTH); }

src/query/frontend/semantic/symbol.hpp

@@ -53,6 +53,8 @@ class Symbol {
   bool user_declared() const { return user_declared_; }
   int token_position() const { return token_position_; }
 
+  bool IsSymbolAnonym() const { return name_.substr(0U, 4U) == "anon"; }
+
   std::string name_;
   int64_t position_;
   bool user_declared_{true};

src/query/frontend/semantic/symbol_generator.cpp

@@ -721,6 +721,32 @@ bool SymbolGenerator::PostVisit(EdgeAtom &) {
   return true;
 }
 
+bool SymbolGenerator::PreVisit(PatternComprehension &pc) {
+  auto &scope = scopes_.back();
+
+  if (scope.in_set_property) {
+    throw utils::NotYetImplemented("Pattern Comprehension cannot be used within SET clause.!");
+  }
+
+  if (scope.in_with) {
+    throw utils::NotYetImplemented("Pattern Comprehension cannot be used within WITH!");
+  }
+
+  if (scope.in_reduce) {
+    throw utils::NotYetImplemented("Pattern Comprehension cannot be used within REDUCE!");
+  }
+
+  if (scope.num_if_operators) {
+    throw utils::NotYetImplemented("IF operator cannot be used with Pattern Comprehension!");
+  }
+
+  const auto &symbol = CreateAnonymousSymbol();
+  pc.MapTo(symbol);
+  return true;
+}
+
+bool SymbolGenerator::PostVisit(PatternComprehension & /*pc*/) { return true; }
+
 void SymbolGenerator::VisitWithIdentifiers(Expression *expr, const std::vector<Identifier *> &identifiers) {
   auto &scope = scopes_.back();
   std::vector<std::pair<std::optional<Symbol>, Identifier *>> prev_symbols;

src/query/frontend/semantic/symbol_generator.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -97,6 +97,8 @@ class SymbolGenerator : public HierarchicalTreeVisitor {
   bool PostVisit(NodeAtom &) override;
   bool PreVisit(EdgeAtom &) override;
   bool PostVisit(EdgeAtom &) override;
+  bool PreVisit(PatternComprehension &) override;
+  bool PostVisit(PatternComprehension &) override;
 
  private:
   // Scope stores the state of where we are when visiting the AST and a map of

src/query/interpreter.cpp

@@ -355,7 +355,7 @@ class ReplQueryHandler {
       const auto replication_config =
           replication::ReplicationClientConfig{.name = name,
                                                .mode = repl_mode,
-                                               .ip_address = ip,
+                                               .ip_address = std::string(ip),
                                                .port = port,
                                                .replica_check_frequency = replica_check_frequency,
                                                .ssl = std::nullopt};
@@ -454,12 +454,12 @@ class CoordQueryHandler final : public query::CoordinatorQueryHandler {
     const auto repl_config = coordination::CoordinatorClientConfig::ReplicationClientInfo{
         .instance_name = std::string(instance_name),
         .replication_mode = convertFromCoordinatorToReplicationMode(sync_mode),
-        .replication_ip_address = replication_ip,
+        .replication_ip_address = std::string(replication_ip),
         .replication_port = replication_port};
 
     auto coordinator_client_config =
         coordination::CoordinatorClientConfig{.instance_name = std::string(instance_name),
-                                              .ip_address = coordinator_server_ip,
+                                              .ip_address = std::string(coordinator_server_ip),
                                               .port = coordinator_server_port,
                                               .instance_health_check_frequency_sec = instance_check_frequency,
                                               .instance_down_timeout_sec = instance_down_timeout,
@@ -497,7 +497,7 @@ class CoordQueryHandler final : public query::CoordinatorQueryHandler {
     auto const maybe_ip_and_port = io::network::Endpoint::ParseSocketOrAddress(raft_socket_address);
     if (maybe_ip_and_port) {
       auto const [ip, port] = *maybe_ip_and_port;
-      spdlog::info("Adding instance {} with raft socket address {}:{}.", raft_server_id, port, ip);
+      spdlog::info("Adding instance {} with raft socket address {}:{}.", raft_server_id, ip, port);
       coordinator_handler_.AddCoordinatorInstance(raft_server_id, port, ip);
     } else {
       spdlog::error("Invalid raft socket address {}.", raft_socket_address);
@@ -1212,7 +1212,7 @@ Callback HandleCoordinatorQuery(CoordinatorQuery *coordinator_query, const Param
       };
 
       notifications->emplace_back(
-          SeverityLevel::INFO, NotificationCode::REGISTER_COORDINATOR_SERVER,
+          SeverityLevel::INFO, NotificationCode::REGISTER_REPLICATION_INSTANCE,
           fmt::format("Coordinator has registered coordinator server on {} for instance {}.",
                       coordinator_socket_address_tv.ValueString(), coordinator_query->instance_name_));
       return callback;
@@ -1263,7 +1263,7 @@ Callback HandleCoordinatorQuery(CoordinatorQuery *coordinator_query, const Param
                   TypedValue{status.coord_socket_address}, TypedValue{status.health}, TypedValue{status.cluster_role}};
         };
 
-        return utils::fmap(converter, instances);
+        return utils::fmap(instances, converter);
       };
       return callback;
     }
@@ -2679,6 +2679,75 @@ PreparedQuery PrepareIndexQuery(ParsedQuery parsed_query, bool in_explicit_trans
       RWType::W};
 }
 
+PreparedQuery PrepareEdgeIndexQuery(ParsedQuery parsed_query, bool in_explicit_transaction,
+                                    std::vector<Notification> *notifications, CurrentDB &current_db) {
+  if (in_explicit_transaction) {
+    throw IndexInMulticommandTxException();
+  }
+
+  auto *index_query = utils::Downcast<EdgeIndexQuery>(parsed_query.query);
+  std::function<void(Notification &)> handler;
+
+  MG_ASSERT(current_db.db_acc_, "Index query expects a current DB");
+  auto &db_acc = *current_db.db_acc_;
+
+  MG_ASSERT(current_db.db_transactional_accessor_, "Index query expects a current DB transaction");
+  auto *dba = &*current_db.execution_db_accessor_;
+
+  auto invalidate_plan_cache = [plan_cache = db_acc->plan_cache()] {
+    plan_cache->WithLock([&](auto &cache) { cache.reset(); });
+  };
+
+  auto *storage = db_acc->storage();
+  auto edge_type = storage->NameToEdgeType(index_query->edge_type_.name);
+
+  Notification index_notification(SeverityLevel::INFO);
+  switch (index_query->action_) {
+    case EdgeIndexQuery::Action::CREATE: {
+      index_notification.code = NotificationCode::CREATE_INDEX;
+      index_notification.title = fmt::format("Created index on edge-type {}.", index_query->edge_type_.name);
+
+      handler = [dba, edge_type, label_name = index_query->edge_type_.name,
+                 invalidate_plan_cache = std::move(invalidate_plan_cache)](Notification &index_notification) {
+        auto maybe_index_error = dba->CreateIndex(edge_type);
+        utils::OnScopeExit invalidator(invalidate_plan_cache);
+
+        if (maybe_index_error.HasError()) {
+          index_notification.code = NotificationCode::EXISTENT_INDEX;
+          index_notification.title = fmt::format("Index on edge-type {} already exists.", label_name);
+        }
+      };
+      break;
+    }
+    case EdgeIndexQuery::Action::DROP: {
+      index_notification.code = NotificationCode::DROP_INDEX;
+      index_notification.title = fmt::format("Dropped index on edge-type {}.", index_query->edge_type_.name);
+      handler = [dba, edge_type, label_name = index_query->edge_type_.name,
+                 invalidate_plan_cache = std::move(invalidate_plan_cache)](Notification &index_notification) {
+        auto maybe_index_error = dba->DropIndex(edge_type);
+        utils::OnScopeExit invalidator(invalidate_plan_cache);
+
+        if (maybe_index_error.HasError()) {
+          index_notification.code = NotificationCode::NONEXISTENT_INDEX;
+          index_notification.title = fmt::format("Index on edge-type {} doesn't exist.", label_name);
+        }
+      };
+      break;
+    }
+  }
+
+  return PreparedQuery{
+      {},
+      std::move(parsed_query.required_privileges),
+      [handler = std::move(handler), notifications, index_notification = std::move(index_notification)](
+          AnyStream * /*stream*/, std::optional<int> /*unused*/) mutable {
+        handler(index_notification);
+        notifications->push_back(index_notification);
+        return QueryHandlerResult::COMMIT;
+      },
+      RWType::W};
+}
+
 PreparedQuery PrepareAuthQuery(ParsedQuery parsed_query, bool in_explicit_transaction,
                                InterpreterContext *interpreter_context, Interpreter &interpreter) {
   if (in_explicit_transaction) {
@@ -3483,6 +3552,7 @@ PreparedQuery PrepareDatabaseInfoQuery(ParsedQuery parsed_query, bool in_explici
         auto *storage = database->storage();
         const std::string_view label_index_mark{"label"};
         const std::string_view label_property_index_mark{"label+property"};
+        const std::string_view edge_type_index_mark{"edge-type"};
         auto info = dba->ListAllIndices();
         auto storage_acc = database->Access();
         std::vector<std::vector<TypedValue>> results;
@@ -3497,6 +3567,10 @@ PreparedQuery PrepareDatabaseInfoQuery(ParsedQuery parsed_query, bool in_explici
                TypedValue(storage->PropertyToName(item.second)),
                TypedValue(static_cast<int>(storage_acc->ApproximateVertexCount(item.first, item.second)))});
         }
+        for (const auto &item : info.edge_type) {
+          results.push_back({TypedValue(edge_type_index_mark), TypedValue(storage->EdgeTypeToName(item)), TypedValue(),
+                             TypedValue(static_cast<int>(storage_acc->ApproximateEdgeCount(item)))});
+        }
         std::sort(results.begin(), results.end(), [&label_index_mark](const auto &record_1, const auto &record_2) {
           const auto type_1 = record_1[0].ValueString();
           const auto type_2 = record_2[0].ValueString();
@@ -4283,13 +4357,14 @@ Interpreter::PrepareResult Interpreter::Prepare(const std::string &query_string,
         utils::Downcast<CypherQuery>(parsed_query.query) || utils::Downcast<ExplainQuery>(parsed_query.query) ||
         utils::Downcast<ProfileQuery>(parsed_query.query) || utils::Downcast<DumpQuery>(parsed_query.query) ||
         utils::Downcast<TriggerQuery>(parsed_query.query) || utils::Downcast<AnalyzeGraphQuery>(parsed_query.query) ||
-        utils::Downcast<IndexQuery>(parsed_query.query) || utils::Downcast<DatabaseInfoQuery>(parsed_query.query) ||
+        utils::Downcast<IndexQuery>(parsed_query.query) || utils::Downcast<EdgeIndexQuery>(parsed_query.query) ||
-        utils::Downcast<ConstraintQuery>(parsed_query.query);
+        utils::Downcast<DatabaseInfoQuery>(parsed_query.query) || utils::Downcast<ConstraintQuery>(parsed_query.query);
 
     if (!in_explicit_transaction_ && requires_db_transaction) {
       // TODO: ATM only a single database, will change when we have multiple database transactions
       bool could_commit = utils::Downcast<CypherQuery>(parsed_query.query) != nullptr;
       bool unique = utils::Downcast<IndexQuery>(parsed_query.query) != nullptr ||
+                    utils::Downcast<EdgeIndexQuery>(parsed_query.query) != nullptr ||
                     utils::Downcast<ConstraintQuery>(parsed_query.query) != nullptr ||
                     upper_case_query.find(kSchemaAssert) != std::string::npos;
       SetupDatabaseTransaction(could_commit, unique);
@@ -4326,6 +4401,9 @@ Interpreter::PrepareResult Interpreter::Prepare(const std::string &query_string,
     } else if (utils::Downcast<IndexQuery>(parsed_query.query)) {
       prepared_query = PrepareIndexQuery(std::move(parsed_query), in_explicit_transaction_,
                                          &query_execution->notifications, current_db_);
+    } else if (utils::Downcast<EdgeIndexQuery>(parsed_query.query)) {
+      prepared_query = PrepareEdgeIndexQuery(std::move(parsed_query), in_explicit_transaction_,
+                                             &query_execution->notifications, current_db_);
     } else if (utils::Downcast<AnalyzeGraphQuery>(parsed_query.query)) {
       prepared_query = PrepareAnalyzeGraphQuery(std::move(parsed_query), in_explicit_transaction_, current_db_);
     } else if (utils::Downcast<AuthQuery>(parsed_query.query)) {

src/query/metadata.cpp

@@ -67,8 +67,8 @@ constexpr std::string_view GetCodeString(const NotificationCode code) {
     case NotificationCode::REGISTER_REPLICA:
       return "RegisterReplica"sv;
 #ifdef MG_ENTERPRISE
-    case NotificationCode::REGISTER_COORDINATOR_SERVER:
+    case NotificationCode::REGISTER_REPLICATION_INSTANCE:
-      return "RegisterCoordinatorServer"sv;
+      return "RegisterReplicationInstance"sv;
     case NotificationCode::ADD_COORDINATOR_INSTANCE:
       return "AddCoordinatorInstance"sv;
     case NotificationCode::UNREGISTER_INSTANCE:

src/query/metadata.hpp

@@ -43,7 +43,7 @@ enum class NotificationCode : uint8_t {
   REPLICA_PORT_WARNING,
   REGISTER_REPLICA,
 #ifdef MG_ENTERPRISE
-  REGISTER_COORDINATOR_SERVER,  // TODO: (andi) What is this?
+  REGISTER_REPLICATION_INSTANCE,
   ADD_COORDINATOR_INSTANCE,
   UNREGISTER_INSTANCE,
 #endif

src/query/plan/hint_provider.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -114,6 +114,9 @@ class PlanHintsProvider final : public HierarchicalLogicalOperatorVisitor {
   bool PreVisit(ScanAllById & /*unused*/) override { return true; }
   bool PostVisit(ScanAllById & /*unused*/) override { return true; }
 
+  bool PreVisit(ScanAllByEdgeType & /*unused*/) override { return true; }
+  bool PostVisit(ScanAllByEdgeType & /*unused*/) override { return true; }
+
   bool PreVisit(ConstructNamedPath & /*unused*/) override { return true; }
   bool PostVisit(ConstructNamedPath & /*unused*/) override { return true; }
 
@@ -206,6 +209,14 @@ class PlanHintsProvider final : public HierarchicalLogicalOperatorVisitor {
 
   bool PostVisit(IndexedJoin & /*unused*/) override { return true; }
 
+  bool PreVisit(RollUpApply &op) override {
+    op.input()->Accept(*this);
+    op.list_collection_branch_->Accept(*this);
+    return false;
+  }
+
+  bool PostVisit(RollUpApply & /*unused*/) override { return true; }
+
  private:
   const SymbolTable &symbol_table_;
   std::vector<std::string> hints_;

src/query/plan/operator.cpp

@@ -105,6 +105,7 @@ extern const Event ScanAllByLabelPropertyRangeOperator;
 extern const Event ScanAllByLabelPropertyValueOperator;
 extern const Event ScanAllByLabelPropertyOperator;
 extern const Event ScanAllByIdOperator;
+extern const Event ScanAllByEdgeTypeOperator;
 extern const Event ExpandOperator;
 extern const Event ExpandVariableOperator;
 extern const Event ConstructNamedPathOperator;
@@ -517,6 +518,60 @@ class ScanAllCursor : public Cursor {
   const char *op_name_;
 };
 
+template <typename TEdgesFun>
+class ScanAllByEdgeTypeCursor : public Cursor {
+ public:
+  explicit ScanAllByEdgeTypeCursor(const ScanAllByEdgeType &self, Symbol output_symbol, UniqueCursorPtr input_cursor,
+                                   storage::View view, TEdgesFun get_edges, const char *op_name)
+      : self_(self),
+        output_symbol_(std::move(output_symbol)),
+        input_cursor_(std::move(input_cursor)),
+        view_(view),
+        get_edges_(std::move(get_edges)),
+        op_name_(op_name) {}
+
+  bool Pull(Frame &frame, ExecutionContext &context) override {
+    OOMExceptionEnabler oom_exception;
+    SCOPED_PROFILE_OP_BY_REF(self_);
+
+    AbortCheck(context);
+
+    while (!vertices_ || vertices_it_.value() == vertices_end_it_.value()) {
+      if (!input_cursor_->Pull(frame, context)) return false;
+      auto next_vertices = get_edges_(frame, context);
+      if (!next_vertices) continue;
+
+      vertices_.emplace(std::move(next_vertices.value()));
+      vertices_it_.emplace(vertices_.value().begin());
+      vertices_end_it_.emplace(vertices_.value().end());
+    }
+
+    frame[output_symbol_] = *vertices_it_.value();
+    ++vertices_it_.value();
+    return true;
+  }
+
+  void Shutdown() override { input_cursor_->Shutdown(); }
+
+  void Reset() override {
+    input_cursor_->Reset();
+    vertices_ = std::nullopt;
+    vertices_it_ = std::nullopt;
+    vertices_end_it_ = std::nullopt;
+  }
+
+ private:
+  const ScanAllByEdgeType &self_;
+  const Symbol output_symbol_;
+  const UniqueCursorPtr input_cursor_;
+  storage::View view_;
+  TEdgesFun get_edges_;
+  std::optional<typename std::result_of<TEdgesFun(Frame &, ExecutionContext &)>::type::value_type> vertices_;
+  std::optional<decltype(vertices_.value().begin())> vertices_it_;
+  std::optional<decltype(vertices_.value().end())> vertices_end_it_;
+  const char *op_name_;
+};
+
 ScanAll::ScanAll(const std::shared_ptr<LogicalOperator> &input, Symbol output_symbol, storage::View view)
     : input_(input ? input : std::make_shared<Once>()), output_symbol_(std::move(output_symbol)), view_(view) {}
 
@@ -556,6 +611,33 @@ UniqueCursorPtr ScanAllByLabel::MakeCursor(utils::MemoryResource *mem) const {
                                                                 view_, std::move(vertices), "ScanAllByLabel");
 }
 
+ScanAllByEdgeType::ScanAllByEdgeType(const std::shared_ptr<LogicalOperator> &input, Symbol output_symbol,
+                                     storage::EdgeTypeId edge_type, storage::View view)
+    : input_(input ? input : std::make_shared<Once>()),
+      output_symbol_(std::move(output_symbol)),
+      view_(view),
+      edge_type_(edge_type) {}
+
+ACCEPT_WITH_INPUT(ScanAllByEdgeType)
+
+UniqueCursorPtr ScanAllByEdgeType::MakeCursor(utils::MemoryResource *mem) const {
+  memgraph::metrics::IncrementCounter(memgraph::metrics::ScanAllByEdgeTypeOperator);
+
+  auto edges = [this](Frame &, ExecutionContext &context) {
+    auto *db = context.db_accessor;
+    return std::make_optional(db->Edges(view_, edge_type_));
+  };
+
+  return MakeUniqueCursorPtr<ScanAllByEdgeTypeCursor<decltype(edges)>>(
+      mem, *this, output_symbol_, input_->MakeCursor(mem), view_, std::move(edges), "ScanAllByEdgeType");
+}
+
+std::vector<Symbol> ScanAllByEdgeType::ModifiedSymbols(const SymbolTable &table) const {
+  auto symbols = input_->ModifiedSymbols(table);
+  symbols.emplace_back(output_symbol_);
+  return symbols;
+}
+
 // TODO(buda): Implement ScanAllByLabelProperty operator to iterate over
 // vertices that have the label and some value for the given property.
 
@@ -5624,4 +5706,25 @@ UniqueCursorPtr HashJoin::MakeCursor(utils::MemoryResource *mem) const {
   return MakeUniqueCursorPtr<HashJoinCursor>(mem, *this, mem);
 }
 
+RollUpApply::RollUpApply(const std::shared_ptr<LogicalOperator> &input,
+                         std::shared_ptr<LogicalOperator> &&second_branch)
+    : input_(input), list_collection_branch_(second_branch) {}
+
+std::vector<Symbol> RollUpApply::OutputSymbols(const SymbolTable & /*symbol_table*/) const {
+  std::vector<Symbol> symbols;
+  return symbols;
+}
+
+std::vector<Symbol> RollUpApply::ModifiedSymbols(const SymbolTable &table) const { return OutputSymbols(table); }
+
+bool RollUpApply::Accept(HierarchicalLogicalOperatorVisitor &visitor) {
+  if (visitor.PreVisit(*this)) {
+    if (!input_ || !list_collection_branch_) {
+      throw utils::NotYetImplemented("One of the branches in pattern comprehension is null! Please contact support.");
+    }
+    input_->Accept(visitor) && list_collection_branch_->Accept(visitor);
+  }
+  return visitor.PostVisit(*this);
+}
+
 }  // namespace memgraph::query::plan

src/query/plan/operator.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -99,6 +99,7 @@ class ScanAllByLabelPropertyRange;
 class ScanAllByLabelPropertyValue;
 class ScanAllByLabelProperty;
 class ScanAllById;
+class ScanAllByEdgeType;
 class Expand;
 class ExpandVariable;
 class ConstructNamedPath;
@@ -130,14 +131,15 @@ class EvaluatePatternFilter;
 class Apply;
 class IndexedJoin;
 class HashJoin;
+class RollUpApply;
 
 using LogicalOperatorCompositeVisitor =
     utils::CompositeVisitor<Once, CreateNode, CreateExpand, ScanAll, ScanAllByLabel, ScanAllByLabelPropertyRange,
-                            ScanAllByLabelPropertyValue, ScanAllByLabelProperty, ScanAllById, Expand, ExpandVariable,
+                            ScanAllByLabelPropertyValue, ScanAllByLabelProperty, ScanAllById, ScanAllByEdgeType, Expand,
-                            ConstructNamedPath, Filter, Produce, Delete, SetProperty, SetProperties, SetLabels,
+                            ExpandVariable, ConstructNamedPath, Filter, Produce, Delete, SetProperty, SetProperties,
-                            RemoveProperty, RemoveLabels, EdgeUniquenessFilter, Accumulate, Aggregate, Skip, Limit,
+                            SetLabels, RemoveProperty, RemoveLabels, EdgeUniquenessFilter, Accumulate, Aggregate, Skip,
-                            OrderBy, Merge, Optional, Unwind, Distinct, Union, Cartesian, CallProcedure, LoadCsv,
+                            Limit, OrderBy, Merge, Optional, Unwind, Distinct, Union, Cartesian, CallProcedure, LoadCsv,
-                            Foreach, EmptyResult, EvaluatePatternFilter, Apply, IndexedJoin, HashJoin>;
+                            Foreach, EmptyResult, EvaluatePatternFilter, Apply, IndexedJoin, HashJoin, RollUpApply>;
 
 using LogicalOperatorLeafVisitor = utils::LeafVisitor<Once>;
 
@@ -591,6 +593,42 @@ class ScanAllByLabel : public memgraph::query::plan::ScanAll {
   }
 };
 
+class ScanAllByEdgeType : public memgraph::query::plan::LogicalOperator {
+ public:
+  static const utils::TypeInfo kType;
+  const utils::TypeInfo &GetTypeInfo() const override { return kType; }
+
+  ScanAllByEdgeType() = default;
+  ScanAllByEdgeType(const std::shared_ptr<LogicalOperator> &input, Symbol output_symbol, storage::EdgeTypeId edge_type,
+                    storage::View view = storage::View::OLD);
+  bool Accept(HierarchicalLogicalOperatorVisitor &visitor) override;
+  UniqueCursorPtr MakeCursor(utils::MemoryResource *) const override;
+  std::vector<Symbol> ModifiedSymbols(const SymbolTable &) const override;
+
+  bool HasSingleInput() const override { return true; }
+  std::shared_ptr<LogicalOperator> input() const override { return input_; }
+  void set_input(std::shared_ptr<LogicalOperator> input) override { input_ = input; }
+
+  std::string ToString() const override {
+    return fmt::format("ScanAllByEdgeType ({} :{})", output_symbol_.name(), dba_->EdgeTypeToName(edge_type_));
+  }
+
+  std::shared_ptr<memgraph::query::plan::LogicalOperator> input_;
+  Symbol output_symbol_;
+  storage::View view_;
+
+  storage::EdgeTypeId edge_type_;
+
+  std::unique_ptr<LogicalOperator> Clone(AstStorage *storage) const override {
+    auto object = std::make_unique<ScanAllByEdgeType>();
+    object->input_ = input_ ? input_->Clone(storage) : nullptr;
+    object->output_symbol_ = output_symbol_;
+    object->view_ = view_;
+    object->edge_type_ = edge_type_;
+    return object;
+  }
+};
+
 /// Behaves like @c ScanAll, but produces only vertices with given label and
 /// property value which is inside a range (inclusive or exlusive).
 ///
@@ -2634,5 +2672,38 @@ class HashJoin : public memgraph::query::plan::LogicalOperator {
   }
 };
 
+/// RollUpApply operator is used to execute an expression which takes as input a pattern,
+/// and returns a list with content from the matched pattern
+/// It's used for a pattern expression or pattern comprehension in a query.
+class RollUpApply : public memgraph::query::plan::LogicalOperator {
+ public:
+  static const utils::TypeInfo kType;
+  const utils::TypeInfo &GetTypeInfo() const override { return kType; }
+
+  RollUpApply() = default;
+  RollUpApply(const std::shared_ptr<LogicalOperator> &input, std::shared_ptr<LogicalOperator> &&second_branch);
+
+  bool HasSingleInput() const override { return false; }
+  std::shared_ptr<LogicalOperator> input() const override { return input_; }
+  void set_input(std::shared_ptr<LogicalOperator> input) override { input_ = input; }
+
+  bool Accept(HierarchicalLogicalOperatorVisitor &visitor) override;
+  UniqueCursorPtr MakeCursor(utils::MemoryResource *) const override {
+    throw utils::NotYetImplemented("Execution of Pattern comprehension is currently unsupported.");
+  }
+  std::vector<Symbol> OutputSymbols(const SymbolTable &) const override;
+  std::vector<Symbol> ModifiedSymbols(const SymbolTable &) const override;
+
+  std::unique_ptr<LogicalOperator> Clone(AstStorage *storage) const override {
+    auto object = std::make_unique<RollUpApply>();
+    object->input_ = input_ ? input_->Clone(storage) : nullptr;
+    object->list_collection_branch_ = list_collection_branch_ ? list_collection_branch_->Clone(storage) : nullptr;
+    return object;
+  }
+
+  std::shared_ptr<memgraph::query::plan::LogicalOperator> input_;
+  std::shared_ptr<memgraph::query::plan::LogicalOperator> list_collection_branch_;
+};
+
 }  // namespace plan
 }  // namespace memgraph::query

src/query/plan/operator_type_info.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -49,6 +49,8 @@ constexpr utils::TypeInfo query::plan::ScanAllByLabelProperty::kType{
 
 constexpr utils::TypeInfo query::plan::ScanAllById::kType{utils::TypeId::SCAN_ALL_BY_ID, "ScanAllById",
                                                           &query::plan::ScanAll::kType};
+constexpr utils::TypeInfo query::plan::ScanAllByEdgeType::kType{utils::TypeId::SCAN_ALL_BY_EDGE_TYPE,
+                                                                "ScanAllByEdgeType", &query::plan::ScanAll::kType};
 
 constexpr utils::TypeInfo query::plan::ExpandCommon::kType{utils::TypeId::EXPAND_COMMON, "ExpandCommon", nullptr};
 
@@ -154,4 +156,7 @@ constexpr utils::TypeInfo query::plan::IndexedJoin::kType{utils::TypeId::INDEXED
 
 constexpr utils::TypeInfo query::plan::HashJoin::kType{utils::TypeId::HASH_JOIN, "HashJoin",
                                                        &query::plan::LogicalOperator::kType};
+
+constexpr utils::TypeInfo query::plan::RollUpApply::kType{utils::TypeId::ROLLUP_APPLY, "RollUpApply",
+                                                          &query::plan::LogicalOperator::kType};
 }  // namespace memgraph

src/query/plan/planner.hpp

@@ -23,6 +23,7 @@
 #include "query/plan/operator.hpp"
 #include "query/plan/preprocess.hpp"
 #include "query/plan/pretty_print.hpp"
+#include "query/plan/rewrite/edge_type_index_lookup.hpp"
 #include "query/plan/rewrite/index_lookup.hpp"
 #include "query/plan/rewrite/join.hpp"
 #include "query/plan/rule_based_planner.hpp"
@@ -54,8 +55,11 @@ class PostProcessor final {
   std::unique_ptr<LogicalOperator> Rewrite(std::unique_ptr<LogicalOperator> plan, TPlanningContext *context) {
     auto index_lookup_plan =
         RewriteWithIndexLookup(std::move(plan), context->symbol_table, context->ast_storage, context->db, index_hints_);
-    return RewriteWithJoinRewriter(std::move(index_lookup_plan), context->symbol_table, context->ast_storage,
+    auto join_plan =
-                                   context->db);
+        RewriteWithJoinRewriter(std::move(index_lookup_plan), context->symbol_table, context->ast_storage, context->db);
+    auto edge_index_plan = RewriteWithEdgeTypeIndexRewriter(std::move(join_plan), context->symbol_table,
+                                                            context->ast_storage, context->db);
+    return edge_index_plan;
   }
 
   template <class TVertexCounts>

src/query/plan/preprocess.cpp

@@ -632,20 +632,20 @@ void AddMatching(const Match &match, SymbolTable &symbol_table, AstStorage &stor
 
   // If there are any pattern filters, we add those as well
   for (auto &filter : matching.filters) {
-    PatternFilterVisitor visitor(symbol_table, storage);
+    PatternVisitor visitor(symbol_table, storage);
 
     filter.expression->Accept(visitor);
-    filter.matchings = visitor.getMatchings();
+    filter.matchings = visitor.getFilterMatchings();
   }
 }
 
-PatternFilterVisitor::PatternFilterVisitor(SymbolTable &symbol_table, AstStorage &storage)
+PatternVisitor::PatternVisitor(SymbolTable &symbol_table, AstStorage &storage)
     : symbol_table_(symbol_table), storage_(storage) {}
-PatternFilterVisitor::PatternFilterVisitor(const PatternFilterVisitor &) = default;
+PatternVisitor::PatternVisitor(const PatternVisitor &) = default;
-PatternFilterVisitor::PatternFilterVisitor(PatternFilterVisitor &&) noexcept = default;
+PatternVisitor::PatternVisitor(PatternVisitor &&) noexcept = default;
-PatternFilterVisitor::~PatternFilterVisitor() = default;
+PatternVisitor::~PatternVisitor() = default;
 
-void PatternFilterVisitor::Visit(Exists &op) {
+void PatternVisitor::Visit(Exists &op) {
   std::vector<Pattern *> patterns;
   patterns.push_back(op.pattern_);
 
@@ -655,10 +655,14 @@ void PatternFilterVisitor::Visit(Exists &op) {
   filter_matching.type = PatternFilterType::EXISTS;
   filter_matching.symbol = std::make_optional<Symbol>(symbol_table_.at(op));
 
-  matchings_.push_back(std::move(filter_matching));
+  filter_matchings_.push_back(std::move(filter_matching));
 }
 
-std::vector<FilterMatching> PatternFilterVisitor::getMatchings() { return matchings_; }
+std::vector<FilterMatching> PatternVisitor::getFilterMatchings() { return filter_matchings_; }
+
+std::vector<PatternComprehensionMatching> PatternVisitor::getPatternComprehensionMatchings() {
+  return pattern_comprehension_matchings_;
+}
 
 static void ParseForeach(query::Foreach &foreach, SingleQueryPart &query_part, AstStorage &storage,
                          SymbolTable &symbol_table) {
@@ -672,6 +676,30 @@ static void ParseForeach(query::Foreach &foreach, SingleQueryPart &query_part, A
   }
 }
 
+static void ParseReturn(query::Return &ret, AstStorage &storage, SymbolTable &symbol_table,
+                        std::unordered_map<std::string, PatternComprehensionMatching> &matchings) {
+  PatternVisitor visitor(symbol_table, storage);
+
+  for (auto *expr : ret.body_.named_expressions) {
+    expr->Accept(visitor);
+    auto pattern_comprehension_matchings = visitor.getPatternComprehensionMatchings();
+    for (auto &matching : pattern_comprehension_matchings) {
+      matchings.emplace(expr->name_, matching);
+    }
+  }
+}
+
+void PatternVisitor::Visit(NamedExpression &op) { op.expression_->Accept(*this); }
+
+void PatternVisitor::Visit(PatternComprehension &op) {
+  PatternComprehensionMatching matching;
+  AddMatching({op.pattern_}, op.filter_, symbol_table_, storage_, matching);
+  matching.result_expr = storage_.Create<NamedExpression>(symbol_table_.at(op).name(), op.resultExpr_);
+  matching.result_expr->MapTo(symbol_table_.at(op));
+
+  pattern_comprehension_matchings_.push_back(std::move(matching));
+}
+
 // Converts a Query to multiple QueryParts. In the process new Ast nodes may be
 // created, e.g. filter expressions.
 std::vector<SingleQueryPart> CollectSingleQueryParts(SymbolTable &symbol_table, AstStorage &storage,
@@ -703,7 +731,8 @@ std::vector<SingleQueryPart> CollectSingleQueryParts(SymbolTable &symbol_table,
         // This query part is done, continue with a new one.
         query_parts.emplace_back(SingleQueryPart{});
         query_part = &query_parts.back();
-      } else if (utils::IsSubtype(*clause, Return::kType)) {
+      } else if (auto *ret = utils::Downcast<Return>(clause)) {
+        ParseReturn(*ret, storage, symbol_table, query_part->pattern_comprehension_matchings);
         return query_parts;
       }
     }

src/query/plan/preprocess.hpp

@@ -153,19 +153,20 @@ struct Expansion {
   ExpansionGroupId expansion_group_id = ExpansionGroupId();
 };
 
+struct PatternComprehensionMatching;
 struct FilterMatching;
 
 enum class PatternFilterType { EXISTS };
 
-/// Collects matchings from filters that include patterns
+/// Collects matchings that include patterns
-class PatternFilterVisitor : public ExpressionVisitor<void> {
+class PatternVisitor : public ExpressionVisitor<void> {
  public:
-  explicit PatternFilterVisitor(SymbolTable &symbol_table, AstStorage &storage);
+  explicit PatternVisitor(SymbolTable &symbol_table, AstStorage &storage);
-  PatternFilterVisitor(const PatternFilterVisitor &);
+  PatternVisitor(const PatternVisitor &);
-  PatternFilterVisitor &operator=(const PatternFilterVisitor &) = delete;
+  PatternVisitor &operator=(const PatternVisitor &) = delete;
-  PatternFilterVisitor(PatternFilterVisitor &&) noexcept;
+  PatternVisitor(PatternVisitor &&) noexcept;
-  PatternFilterVisitor &operator=(PatternFilterVisitor &&) noexcept = delete;
+  PatternVisitor &operator=(PatternVisitor &&) noexcept = delete;
-  ~PatternFilterVisitor() override;
+  ~PatternVisitor() override;
 
   using ExpressionVisitor<void>::Visit;
 
@@ -233,18 +234,22 @@ class PatternFilterVisitor : public ExpressionVisitor<void> {
   void Visit(PropertyLookup &op) override{};
   void Visit(AllPropertiesLookup &op) override{};
   void Visit(ParameterLookup &op) override{};
-  void Visit(NamedExpression &op) override{};
   void Visit(RegexMatch &op) override{};
-  void Visit(PatternComprehension &op) override{};
+  void Visit(NamedExpression &op) override;
+  void Visit(PatternComprehension &op) override;
 
-  std::vector<FilterMatching> getMatchings();
+  std::vector<FilterMatching> getFilterMatchings();
+  std::vector<PatternComprehensionMatching> getPatternComprehensionMatchings();
 
   SymbolTable &symbol_table_;
   AstStorage &storage_;
 
  private:
   /// Collection of matchings in the filter expression being analyzed.
-  std::vector<FilterMatching> matchings_;
+  std::vector<FilterMatching> filter_matchings_;
+
+  /// Collection of matchings in the pattern comprehension being analyzed.
+  std::vector<PatternComprehensionMatching> pattern_comprehension_matchings_;
 };
 
 /// Stores the symbols and expression used to filter a property.
@@ -495,6 +500,11 @@ inline auto Filters::IdFilters(const Symbol &symbol) const -> std::vector<Filter
   return filters;
 }
 
+struct PatternComprehensionMatching : Matching {
+  /// Pattern comprehension result named expression
+  NamedExpression *result_expr = nullptr;
+};
+
 /// @brief Represents a read (+ write) part of a query. Parts are split on
 /// `WITH` clauses.
 ///
@@ -537,6 +547,14 @@ struct SingleQueryPart {
   /// in the `remaining_clauses` but rather in the `Foreach` itself and are guranteed
   /// to be processed in the same order by the semantics of the `RuleBasedPlanner`.
   std::vector<Matching> merge_matching{};
+
+  /// @brief @c NamedExpression name to @c PatternComprehensionMatching for each pattern comprehension.
+  ///
+  /// Storing the normalized pattern of a @c PatternComprehension does not preclude storing the
+  /// @c PatternComprehension clause itself inside `remaining_clauses`. The reason is that we
+  /// need to have access to other parts of the clause, such as pattern, filter clauses.
+  std::unordered_map<std::string, PatternComprehensionMatching> pattern_comprehension_matchings{};
+
   /// @brief All the remaining clauses (without @c Match).
   std::vector<Clause *> remaining_clauses{};
   /// The subqueries vector are all the subqueries in this query part ordered in a list by

src/query/plan/pretty_print.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -76,6 +76,13 @@ bool PlanPrinter::PreVisit(ScanAllById &op) {
   return true;
 }
 
+bool PlanPrinter::PreVisit(query::plan::ScanAllByEdgeType &op) {
+  op.dba_ = dba_;
+  WithPrintLn([&op](auto &out) { out << "* " << op.ToString(); });
+  op.dba_ = nullptr;
+  return true;
+}
+
 bool PlanPrinter::PreVisit(query::plan::Expand &op) {
   op.dba_ = dba_;
   WithPrintLn([&op](auto &out) { out << "* " << op.ToString(); });
@@ -143,6 +150,13 @@ bool PlanPrinter::PreVisit(query::plan::Union &op) {
   return false;
 }
 
+bool PlanPrinter::PreVisit(query::plan::RollUpApply &op) {
+  WithPrintLn([&op](auto &out) { out << "* " << op.ToString(); });
+  Branch(*op.list_collection_branch_);
+  op.input_->Accept(*this);
+  return false;
+}
+
 bool PlanPrinter::PreVisit(query::plan::CallProcedure &op) {
   WithPrintLn([&op](auto &out) { out << "* " << op.ToString(); });
   return true;
@@ -457,6 +471,19 @@ bool PlanToJsonVisitor::PreVisit(ScanAllById &op) {
   return false;
 }
 
+bool PlanToJsonVisitor::PreVisit(ScanAllByEdgeType &op) {
+  json self;
+  self["name"] = "ScanAllByEdgeType";
+  self["edge_type"] = ToJson(op.edge_type_, *dba_);
+  self["output_symbol"] = ToJson(op.output_symbol_);
+
+  op.input_->Accept(*this);
+  self["input"] = PopOutput();
+
+  output_ = std::move(self);
+  return false;
+}
+
 bool PlanToJsonVisitor::PreVisit(CreateNode &op) {
   json self;
   self["name"] = "CreateNode";

src/query/plan/pretty_print.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -67,6 +67,7 @@ class PlanPrinter : public virtual HierarchicalLogicalOperatorVisitor {
   bool PreVisit(ScanAllByLabelPropertyRange &) override;
   bool PreVisit(ScanAllByLabelProperty &) override;
   bool PreVisit(ScanAllById &) override;
+  bool PreVisit(ScanAllByEdgeType &) override;
 
   bool PreVisit(Expand &) override;
   bool PreVisit(ExpandVariable &) override;
@@ -91,6 +92,7 @@ class PlanPrinter : public virtual HierarchicalLogicalOperatorVisitor {
   bool PreVisit(OrderBy &) override;
   bool PreVisit(Distinct &) override;
   bool PreVisit(Union &) override;
+  bool PreVisit(RollUpApply &) override;
 
   bool PreVisit(Unwind &) override;
   bool PreVisit(CallProcedure &) override;
@@ -203,6 +205,7 @@ class PlanToJsonVisitor : public virtual HierarchicalLogicalOperatorVisitor {
   bool PreVisit(ScanAllByLabelPropertyValue &) override;
   bool PreVisit(ScanAllByLabelProperty &) override;
   bool PreVisit(ScanAllById &) override;
+  bool PreVisit(ScanAllByEdgeType &) override;
 
   bool PreVisit(EmptyResult &) override;
   bool PreVisit(Produce &) override;

src/query/plan/rewrite/edge_type_index_lookup.hpp

@@ -0,0 +1,534 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+/// @file
+/// This file provides a plan rewriter which replaces `ScanAll` and `Expand`
+/// operations with `ScanAllByEdgeType` if possible. The public entrypoint is
+/// `RewriteWithEdgeTypeIndexRewriter`.
+
+#pragma once
+
+#include <algorithm>
+#include <memory>
+#include <optional>
+#include <unordered_map>
+#include <unordered_set>
+#include <vector>
+
+#include <gflags/gflags.h>
+
+#include "query/plan/operator.hpp"
+#include "query/plan/preprocess.hpp"
+#include "query/plan/rewrite/index_lookup.hpp"
+#include "utils/algorithm.hpp"
+
+namespace memgraph::query::plan {
+
+namespace impl {
+
+template <class TDbAccessor>
+class EdgeTypeIndexRewriter final : public HierarchicalLogicalOperatorVisitor {
+ public:
+  EdgeTypeIndexRewriter(SymbolTable *symbol_table, AstStorage *ast_storage, TDbAccessor *db)
+      : symbol_table_(symbol_table), ast_storage_(ast_storage), db_(db) {}
+
+  using HierarchicalLogicalOperatorVisitor::PostVisit;
+  using HierarchicalLogicalOperatorVisitor::PreVisit;
+  using HierarchicalLogicalOperatorVisitor::Visit;
+
+  bool Visit(Once &) override { return true; }
+
+  bool PreVisit(Filter &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(Filter & /*op*/) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAll &op) override {
+    prev_ops_.push_back(&op);
+
+    if (op.input()->GetTypeInfo() == Once::kType) {
+      const bool is_node_anon = op.output_symbol_.IsSymbolAnonym();
+      once_under_scanall_ = is_node_anon;
+    }
+
+    return true;
+  }
+
+  bool PostVisit(ScanAll &op) override {
+    prev_ops_.pop_back();
+
+    if (EdgeTypeIndexingPossible()) {
+      SetOnParent(op.input());
+    }
+
+    return true;
+  }
+
+  bool PreVisit(Expand &op) override {
+    prev_ops_.push_back(&op);
+
+    if (op.input()->GetTypeInfo() == ScanAll::kType) {
+      const bool only_one_edge_type = (op.common_.edge_types.size() == 1U);
+      const bool expansion_is_named = !(op.common_.edge_symbol.IsSymbolAnonym());
+      const bool expdanded_node_not_named = op.common_.node_symbol.IsSymbolAnonym();
+
+      edge_type_index_exist = only_one_edge_type ? db_->EdgeTypeIndexExists(op.common_.edge_types.front()) : false;
+
+      scanall_under_expand_ = only_one_edge_type && expansion_is_named && expdanded_node_not_named;
+    }
+
+    return true;
+  }
+
+  bool PostVisit(Expand &op) override {
+    prev_ops_.pop_back();
+
+    if (EdgeTypeIndexingPossible()) {
+      auto indexed_scan = GenEdgeTypeScan(op);
+      SetOnParent(std::move(indexed_scan));
+    }
+
+    return true;
+  }
+
+  bool PreVisit(ExpandVariable &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(ExpandVariable &expand) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Merge &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.merge_match_);
+    return false;
+  }
+
+  bool PostVisit(Merge &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Optional &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.optional_);
+    return false;
+  }
+
+  bool PostVisit(Optional &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Cartesian &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(Cartesian &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(IndexedJoin &op) override {
+    prev_ops_.push_back(&op);
+    RewriteBranch(&op.main_branch_);
+    RewriteBranch(&op.sub_branch_);
+    return false;
+  }
+
+  bool PostVisit(IndexedJoin &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(HashJoin &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(HashJoin &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Union &op) override {
+    prev_ops_.push_back(&op);
+    RewriteBranch(&op.left_op_);
+    RewriteBranch(&op.right_op_);
+    return false;
+  }
+
+  bool PostVisit(Union &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(CreateNode &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(CreateNode &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(CreateExpand &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(CreateExpand &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllByLabel &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllByLabel &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllByLabelPropertyRange &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllByLabelPropertyRange &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllByLabelPropertyValue &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllByLabelPropertyValue &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllByLabelProperty &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllByLabelProperty &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllById &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllById &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ScanAllByEdgeType &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ScanAllByEdgeType &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(ConstructNamedPath &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(ConstructNamedPath &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Produce &op) override {
+    prev_ops_.push_back(&op);
+
+    if (op.input()->GetTypeInfo() == Expand::kType) {
+      expand_under_produce_ = true;
+    }
+
+    return true;
+  }
+  bool PostVisit(Produce &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(EmptyResult &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(EmptyResult &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Delete &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Delete &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(SetProperty &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(SetProperty &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(SetProperties &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(SetProperties &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(SetLabels &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(SetLabels &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(RemoveProperty &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(RemoveProperty &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(RemoveLabels &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(RemoveLabels &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(EdgeUniquenessFilter &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(EdgeUniquenessFilter &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Accumulate &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Accumulate &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Aggregate &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Aggregate &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Skip &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Skip &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Limit &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Limit &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(OrderBy &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(OrderBy &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Unwind &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Unwind &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Distinct &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(Distinct &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(CallProcedure &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+  bool PostVisit(CallProcedure &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Foreach &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.update_clauses_);
+    return false;
+  }
+
+  bool PostVisit(Foreach &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(EvaluatePatternFilter &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(EvaluatePatternFilter & /*op*/) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(Apply &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.subquery_);
+    return false;
+  }
+
+  bool PostVisit(Apply & /*op*/) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  bool PreVisit(LoadCsv &op) override {
+    prev_ops_.push_back(&op);
+    return true;
+  }
+
+  bool PostVisit(LoadCsv & /*op*/) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
+  std::shared_ptr<LogicalOperator> new_root_;
+
+ private:
+  SymbolTable *symbol_table_;
+  AstStorage *ast_storage_;
+  TDbAccessor *db_;
+  // Collected filters, pending for examination if they can be used for advanced
+  // lookup operations (by index, node ID, ...).
+  Filters filters_;
+  // Expressions which no longer need a plain Filter operator.
+  std::unordered_set<Expression *> filter_exprs_for_removal_;
+  std::vector<LogicalOperator *> prev_ops_;
+  std::unordered_set<Symbol> cartesian_symbols_;
+
+  bool EdgeTypeIndexingPossible() const {
+    return expand_under_produce_ && scanall_under_expand_ && once_under_scanall_ && edge_type_index_exist;
+  }
+  bool expand_under_produce_ = false;
+  bool scanall_under_expand_ = false;
+  bool once_under_scanall_ = false;
+  bool edge_type_index_exist = false;
+
+  bool DefaultPreVisit() override {
+    throw utils::NotYetImplemented("Operator not yet covered by EdgeTypeIndexRewriter");
+  }
+
+  std::unique_ptr<ScanAllByEdgeType> GenEdgeTypeScan(const Expand &expand) {
+    const auto &input = expand.input();
+    const auto &output_symbol = expand.common_.edge_symbol;
+    const auto &view = expand.view_;
+
+    // Extract edge_type from symbol
+    auto edge_type = expand.common_.edge_types.front();
+    return std::make_unique<ScanAllByEdgeType>(input, output_symbol, edge_type, view);
+  }
+
+  void SetOnParent(const std::shared_ptr<LogicalOperator> &input) {
+    MG_ASSERT(input);
+    if (prev_ops_.empty()) {
+      MG_ASSERT(!new_root_);
+      new_root_ = input;
+      return;
+    }
+    prev_ops_.back()->set_input(input);
+  }
+
+  void RewriteBranch(std::shared_ptr<LogicalOperator> *branch) {
+    EdgeTypeIndexRewriter<TDbAccessor> rewriter(symbol_table_, ast_storage_, db_);
+    (*branch)->Accept(rewriter);
+    if (rewriter.new_root_) {
+      *branch = rewriter.new_root_;
+    }
+  }
+};
+
+}  // namespace impl
+
+template <class TDbAccessor>
+std::unique_ptr<LogicalOperator> RewriteWithEdgeTypeIndexRewriter(std::unique_ptr<LogicalOperator> root_op,
+                                                                  SymbolTable *symbol_table, AstStorage *ast_storage,
+                                                                  TDbAccessor *db) {
+  impl::EdgeTypeIndexRewriter<TDbAccessor> rewriter(symbol_table, ast_storage, db);
+  root_op->Accept(rewriter);
+  return root_op;
+}
+
+}  // namespace memgraph::query::plan

src/query/plan/rewrite/index_lookup.hpp

@@ -595,6 +595,18 @@ class IndexLookupRewriter final : public HierarchicalLogicalOperatorVisitor {
     return true;
   }
 
+  bool PreVisit(RollUpApply &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.list_collection_branch_);
+    return false;
+  }
+
+  bool PostVisit(RollUpApply &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
   std::shared_ptr<LogicalOperator> new_root_;
 
  private:

src/query/plan/rewrite/join.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -455,6 +455,18 @@ class JoinRewriter final : public HierarchicalLogicalOperatorVisitor {
     return true;
   }
 
+  bool PreVisit(RollUpApply &op) override {
+    prev_ops_.push_back(&op);
+    op.input()->Accept(*this);
+    RewriteBranch(&op.list_collection_branch_);
+    return false;
+  }
+
+  bool PostVisit(RollUpApply &) override {
+    prev_ops_.pop_back();
+    return true;
+  }
+
   std::shared_ptr<LogicalOperator> new_root_;
 
  private:

src/query/plan/rule_based_planner.cpp

@@ -14,9 +14,12 @@
 #include <algorithm>
 #include <functional>
 #include <limits>
+#include <memory>
 #include <stack>
 #include <unordered_set>
 
+#include "query/frontend/ast/ast.hpp"
+#include "query/plan/operator.hpp"
 #include "query/plan/preprocess.hpp"
 #include "utils/algorithm.hpp"
 #include "utils/exceptions.hpp"
@@ -40,7 +43,8 @@ namespace {
 class ReturnBodyContext : public HierarchicalTreeVisitor {
  public:
   ReturnBodyContext(const ReturnBody &body, SymbolTable &symbol_table, const std::unordered_set<Symbol> &bound_symbols,
-                    AstStorage &storage, Where *where = nullptr)
+                    AstStorage &storage, std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops,
+                    Where *where = nullptr)
       : body_(body), symbol_table_(symbol_table), bound_symbols_(bound_symbols), storage_(storage), where_(where) {
     // Collect symbols from named expressions.
     output_symbols_.reserve(body_.named_expressions.size());
@@ -53,6 +57,14 @@ class ReturnBodyContext : public HierarchicalTreeVisitor {
       output_symbols_.emplace_back(symbol_table_.at(*named_expr));
       named_expr->Accept(*this);
       named_expressions_.emplace_back(named_expr);
+      if (pattern_comprehension_) {
+        if (auto it = pc_ops.find(named_expr->name_); it != pc_ops.end()) {
+          pattern_comprehension_op_ = std::move(it->second);
+          pc_ops.erase(it);
+        } else {
+          throw utils::NotYetImplemented("Operation on top of pattern comprehension");
+        }
+      }
     }
     // Collect symbols used in group by expressions.
     if (!aggregations_.empty()) {
@@ -386,8 +398,20 @@ class ReturnBodyContext : public HierarchicalTreeVisitor {
     return true;
   }
 
-  bool PostVisit(PatternComprehension & /*unused*/) override {
+  bool PreVisit(PatternComprehension & /*unused*/) override {
-    throw utils::NotYetImplemented("Planner can not handle pattern comprehension.");
+    pattern_compression_aggregations_start_index_ = has_aggregation_.size();
+    return true;
+  }
+
+  bool PostVisit(PatternComprehension &pattern_comprehension) override {
+    bool has_aggr = false;
+    for (auto i = has_aggregation_.size(); i > pattern_compression_aggregations_start_index_; --i) {
+      has_aggr |= has_aggregation_.back();
+      has_aggregation_.pop_back();
+    }
+    has_aggregation_.emplace_back(has_aggr);
+    pattern_comprehension_ = &pattern_comprehension;
+    return true;
   }
 
   // Creates NamedExpression with an Identifier for each user declared symbol.
@@ -444,6 +468,10 @@ class ReturnBodyContext : public HierarchicalTreeVisitor {
   // named_expressions.
   const auto &output_symbols() const { return output_symbols_; }
 
+  const auto *pattern_comprehension() const { return pattern_comprehension_; }
+
+  std::shared_ptr<LogicalOperator> pattern_comprehension_op() const { return pattern_comprehension_op_; }
+
  private:
   const ReturnBody &body_;
   SymbolTable &symbol_table_;
@@ -465,10 +493,13 @@ class ReturnBodyContext : public HierarchicalTreeVisitor {
   //                      group by it.
   std::list<bool> has_aggregation_;
   std::vector<NamedExpression *> named_expressions_;
+  PatternComprehension *pattern_comprehension_ = nullptr;
+  std::shared_ptr<LogicalOperator> pattern_comprehension_op_;
+  size_t pattern_compression_aggregations_start_index_ = 0;
 };
 
 std::unique_ptr<LogicalOperator> GenReturnBody(std::unique_ptr<LogicalOperator> input_op, bool advance_command,
-                                               const ReturnBodyContext &body, bool accumulate = false) {
+                                               const ReturnBodyContext &body, bool accumulate) {
   std::vector<Symbol> used_symbols(body.used_symbols().begin(), body.used_symbols().end());
   auto last_op = std::move(input_op);
   if (accumulate) {
@@ -482,6 +513,11 @@ std::unique_ptr<LogicalOperator> GenReturnBody(std::unique_ptr<LogicalOperator>
     std::vector<Symbol> remember(body.group_by_used_symbols().begin(), body.group_by_used_symbols().end());
     last_op = std::make_unique<Aggregate>(std::move(last_op), body.aggregations(), body.group_by(), remember);
   }
+
+  if (body.pattern_comprehension()) {
+    last_op = std::make_unique<RollUpApply>(std::move(last_op), body.pattern_comprehension_op());
+  }
+
   last_op = std::make_unique<Produce>(std::move(last_op), body.named_expressions());
   // Distinct in ReturnBody only makes Produce values unique, so plan after it.
   if (body.distinct()) {
@@ -506,6 +542,7 @@ std::unique_ptr<LogicalOperator> GenReturnBody(std::unique_ptr<LogicalOperator>
     last_op = std::make_unique<Filter>(std::move(last_op), std::vector<std::shared_ptr<LogicalOperator>>{},
                                        body.where()->expression_);
   }
+
   return last_op;
 }
 
@@ -543,8 +580,9 @@ Expression *ExtractFilters(const std::unordered_set<Symbol> &bound_symbols, Filt
   return filter_expr;
 }
 
-std::unordered_set<Symbol> GetSubqueryBoundSymbols(const std::vector<SingleQueryPart> &single_query_parts,
+std::unordered_set<Symbol> GetSubqueryBoundSymbols(
-                                                   SymbolTable &symbol_table, AstStorage &storage) {
+    const std::vector<SingleQueryPart> &single_query_parts, SymbolTable &symbol_table, AstStorage &storage,
+    std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops) {
   const auto &query = single_query_parts[0];
 
   if (!query.matching.expansions.empty() || query.remaining_clauses.empty()) {
@@ -552,7 +590,7 @@ std::unordered_set<Symbol> GetSubqueryBoundSymbols(const std::vector<SingleQuery
   }
 
   if (std::unordered_set<Symbol> bound_symbols; auto *with = utils::Downcast<query::With>(query.remaining_clauses[0])) {
-    auto input_op = impl::GenWith(*with, nullptr, symbol_table, false, bound_symbols, storage);
+    auto input_op = impl::GenWith(*with, nullptr, symbol_table, false, bound_symbols, storage, pc_ops);
     return bound_symbols;
   }
 
@@ -583,7 +621,8 @@ std::unique_ptr<LogicalOperator> GenNamedPaths(std::unique_ptr<LogicalOperator>
 
 std::unique_ptr<LogicalOperator> GenReturn(Return &ret, std::unique_ptr<LogicalOperator> input_op,
                                            SymbolTable &symbol_table, bool is_write,
-                                           const std::unordered_set<Symbol> &bound_symbols, AstStorage &storage) {
+                                           const std::unordered_set<Symbol> &bound_symbols, AstStorage &storage,
+                                           std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops) {
   // Similar to WITH clause, but we want to accumulate when the query writes to
   // the database. This way we handle the case when we want to return
   // expressions with the latest updated results. For example, `MATCH (n) -- ()
@@ -592,13 +631,14 @@ std::unique_ptr<LogicalOperator> GenReturn(Return &ret, std::unique_ptr<LogicalO
   // final result of 'k' increments.
   bool accumulate = is_write;
   bool advance_command = false;
-  ReturnBodyContext body(ret.body_, symbol_table, bound_symbols, storage);
+  ReturnBodyContext body(ret.body_, symbol_table, bound_symbols, storage, pc_ops);
   return GenReturnBody(std::move(input_op), advance_command, body, accumulate);
 }
 
 std::unique_ptr<LogicalOperator> GenWith(With &with, std::unique_ptr<LogicalOperator> input_op,
                                          SymbolTable &symbol_table, bool is_write,
-                                         std::unordered_set<Symbol> &bound_symbols, AstStorage &storage) {
+                                         std::unordered_set<Symbol> &bound_symbols, AstStorage &storage,
+                                         std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops) {
   // WITH clause is Accumulate/Aggregate (advance_command) + Produce and
   // optional Filter. In case of update and aggregation, we want to accumulate
   // first, so that when aggregating, we get the latest results. Similar to
@@ -606,7 +646,7 @@ std::unique_ptr<LogicalOperator> GenWith(With &with, std::unique_ptr<LogicalOper
   bool accumulate = is_write;
   // No need to advance the command if we only performed reads.
   bool advance_command = is_write;
-  ReturnBodyContext body(with.body_, symbol_table, bound_symbols, storage, with.where_);
+  ReturnBodyContext body(with.body_, symbol_table, bound_symbols, storage, pc_ops, with.where_);
   auto last_op = GenReturnBody(std::move(input_op), advance_command, body, accumulate);
   // Reset bound symbols, so that only those in WITH are exposed.
   bound_symbols.clear();

src/query/plan/rule_based_planner.hpp

@@ -21,6 +21,7 @@
 #include "query/frontend/ast/ast_visitor.hpp"
 #include "query/plan/operator.hpp"
 #include "query/plan/preprocess.hpp"
+#include "utils/exceptions.hpp"
 #include "utils/logging.hpp"
 #include "utils/typeinfo.hpp"
 
@@ -87,8 +88,9 @@ bool HasBoundFilterSymbols(const std::unordered_set<Symbol> &bound_symbols, cons
 
 // Returns the set of symbols for the subquery that are actually referenced from the outer scope and
 // used in the subquery.
-std::unordered_set<Symbol> GetSubqueryBoundSymbols(const std::vector<SingleQueryPart> &single_query_parts,
+std::unordered_set<Symbol> GetSubqueryBoundSymbols(
-                                                   SymbolTable &symbol_table, AstStorage &storage);
+    const std::vector<SingleQueryPart> &single_query_parts, SymbolTable &symbol_table, AstStorage &storage,
+    std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops);
 
 Symbol GetSymbol(NodeAtom *atom, const SymbolTable &symbol_table);
 Symbol GetSymbol(EdgeAtom *atom, const SymbolTable &symbol_table);
@@ -142,11 +144,13 @@ std::unique_ptr<LogicalOperator> GenNamedPaths(std::unique_ptr<LogicalOperator>
 
 std::unique_ptr<LogicalOperator> GenReturn(Return &ret, std::unique_ptr<LogicalOperator> input_op,
                                            SymbolTable &symbol_table, bool is_write,
-                                           const std::unordered_set<Symbol> &bound_symbols, AstStorage &storage);
+                                           const std::unordered_set<Symbol> &bound_symbols, AstStorage &storage,
+                                           std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops);
 
 std::unique_ptr<LogicalOperator> GenWith(With &with, std::unique_ptr<LogicalOperator> input_op,
                                          SymbolTable &symbol_table, bool is_write,
-                                         std::unordered_set<Symbol> &bound_symbols, AstStorage &storage);
+                                         std::unordered_set<Symbol> &bound_symbols, AstStorage &storage,
+                                         std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops);
 
 std::unique_ptr<LogicalOperator> GenUnion(const CypherUnion &cypher_union, std::shared_ptr<LogicalOperator> left_op,
                                           std::shared_ptr<LogicalOperator> right_op, SymbolTable &symbol_table);
@@ -190,11 +194,24 @@ class RuleBasedPlanner {
         uint64_t merge_id = 0;
         uint64_t subquery_id = 0;
 
+        std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pattern_comprehension_ops;
+
+        if (single_query_part.pattern_comprehension_matchings.size() > 1) {
+          throw utils::NotYetImplemented("Multiple pattern comprehensions.");
+        }
+        for (const auto &matching : single_query_part.pattern_comprehension_matchings) {
+          std::unique_ptr<LogicalOperator> new_input;
+          MatchContext match_ctx{matching.second, *context.symbol_table, context.bound_symbols};
+          new_input = PlanMatching(match_ctx, std::move(new_input));
+          new_input = std::make_unique<Produce>(std::move(new_input), std::vector{matching.second.result_expr});
+          pattern_comprehension_ops.emplace(matching.first, std::move(new_input));
+        }
+
         for (const auto &clause : single_query_part.remaining_clauses) {
           MG_ASSERT(!utils::IsSubtype(*clause, Match::kType), "Unexpected Match in remaining clauses");
           if (auto *ret = utils::Downcast<Return>(clause)) {
             input_op = impl::GenReturn(*ret, std::move(input_op), *context.symbol_table, context.is_write_query,
-                                       context.bound_symbols, *context.ast_storage);
+                                       context.bound_symbols, *context.ast_storage, pattern_comprehension_ops);
           } else if (auto *merge = utils::Downcast<query::Merge>(clause)) {
             input_op = GenMerge(*merge, std::move(input_op), single_query_part.merge_matching[merge_id++]);
             // Treat MERGE clause as write, because we do not know if it will
@@ -202,7 +219,7 @@ class RuleBasedPlanner {
             context.is_write_query = true;
           } else if (auto *with = utils::Downcast<query::With>(clause)) {
             input_op = impl::GenWith(*with, std::move(input_op), *context.symbol_table, context.is_write_query,
-                                     context.bound_symbols, *context.ast_storage);
+                                     context.bound_symbols, *context.ast_storage, pattern_comprehension_ops);
             // WITH clause advances the command, so reset the flag.
             context.is_write_query = false;
           } else if (auto op = HandleWriteClause(clause, input_op, *context.symbol_table, context.bound_symbols)) {
@@ -241,7 +258,7 @@ class RuleBasedPlanner {
                                            single_query_part, merge_id);
           } else if (auto *call_sub = utils::Downcast<query::CallSubquery>(clause)) {
             input_op = HandleSubquery(std::move(input_op), single_query_part.subqueries[subquery_id++],
-                                      *context.symbol_table, *context_->ast_storage);
+                                      *context.symbol_table, *context_->ast_storage, pattern_comprehension_ops);
           } else {
             throw utils::NotYetImplemented("clause '{}' conversion to operator(s)", clause->GetTypeInfo().name);
           }
@@ -860,15 +877,15 @@ class RuleBasedPlanner {
                                            symbol);
   }
 
-  std::unique_ptr<LogicalOperator> HandleSubquery(std::unique_ptr<LogicalOperator> last_op,
+  std::unique_ptr<LogicalOperator> HandleSubquery(
-                                                  std::shared_ptr<QueryParts> subquery, SymbolTable &symbol_table,
+      std::unique_ptr<LogicalOperator> last_op, std::shared_ptr<QueryParts> subquery, SymbolTable &symbol_table,
-                                                  AstStorage &storage) {
+      AstStorage &storage, std::unordered_map<std::string, std::shared_ptr<LogicalOperator>> pc_ops) {
     std::unordered_set<Symbol> outer_scope_bound_symbols;
     outer_scope_bound_symbols.insert(std::make_move_iterator(context_->bound_symbols.begin()),
                                      std::make_move_iterator(context_->bound_symbols.end()));
 
     context_->bound_symbols =
-        impl::GetSubqueryBoundSymbols(subquery->query_parts[0].single_query_parts, symbol_table, storage);
+        impl::GetSubqueryBoundSymbols(subquery->query_parts[0].single_query_parts, symbol_table, storage, pc_ops);
 
     auto subquery_op = Plan(*subquery);
 

src/query/plan/vertex_count_cache.hpp

@@ -78,6 +78,8 @@ class VertexCountCache {
     return db_->LabelPropertyIndexExists(label, property);
   }
 
+  bool EdgeTypeIndexExists(storage::EdgeTypeId edge_type) { return db_->EdgeTypeIndexExists(edge_type); }
+
   std::optional<storage::LabelIndexStats> GetIndexStats(const storage::LabelId &label) const {
     return db_->GetIndexStats(label);
   }

src/query/procedure/module.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/query/procedure/py_module.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/replication_coordination_glue/mode.hpp

@@ -16,28 +16,15 @@
 #include <stdexcept>
 #include <string>
 
+#include "json/json.hpp"
+
 namespace memgraph::replication_coordination_glue {
 
 enum class ReplicationMode : std::uint8_t { SYNC, ASYNC };
 
-inline auto ReplicationModeToString(ReplicationMode mode) -> std::string {
+NLOHMANN_JSON_SERIALIZE_ENUM(ReplicationMode, {
-  switch (mode) {
+                                                  {ReplicationMode::SYNC, "sync"},
-    case ReplicationMode::SYNC:
+                                                  {ReplicationMode::ASYNC, "async"},
-      return "SYNC";
+                                              })
-    case ReplicationMode::ASYNC:
-      return "ASYNC";
-  }
-  throw std::invalid_argument("Invalid replication mode");
-}
-
-inline auto ReplicationModeFromString(std::string_view mode) -> ReplicationMode {
-  if (mode == "SYNC") {
-    return ReplicationMode::SYNC;
-  }
-  if (mode == "ASYNC") {
-    return ReplicationMode::ASYNC;
-  }
-  throw std::invalid_argument("Invalid replication mode");
-}
 
 }  // namespace memgraph::replication_coordination_glue

src/replication_coordination_glue/role.hpp

@@ -12,8 +12,14 @@
 #pragma once
 
 #include <cstdint>
+
+#include "json/json.hpp"
+
 namespace memgraph::replication_coordination_glue {
 
 // TODO: figure out a way of ensuring that usage of this type is never uninitialed/defaulted incorrectly to MAIN
 enum class ReplicationRole : uint8_t { MAIN, REPLICA };
+
+NLOHMANN_JSON_SERIALIZE_ENUM(ReplicationRole, {{ReplicationRole::MAIN, "main"}, {ReplicationRole::REPLICA, "replica"}})
+
 }  // namespace memgraph::replication_coordination_glue

src/replication_handler/include/replication_handler/replication_handler.hpp

@@ -210,8 +210,13 @@ struct ReplicationHandler : public memgraph::query::ReplicationQueryHandler {
             auto client = std::make_unique<storage::ReplicationStorageClient>(*instance_client_ptr, main_uuid);
             client->Start(storage, std::move(db_acc));
             bool const success = std::invoke([state = client->State()]() {
+              // We force sync replicas in other situation
               if (state == storage::replication::ReplicaState::DIVERGED_FROM_MAIN) {
+#ifdef MG_ENTERPRISE
+                return FLAGS_coordinator_server_port != 0;
+#else
                 return false;
+#endif
               }
               return true;
             });

src/replication_handler/replication_handler.cpp

@@ -271,8 +271,7 @@ auto ReplicationHandler::GetDatabasesHistories() -> replication_coordination_glu
   dbms_handler_.ForEach([&results](memgraph::dbms::DatabaseAccess db_acc) {
     auto &repl_storage_state = db_acc->storage()->repl_storage_state_;
 
-    std::vector<std::pair<std::string, uint64_t>> history = utils::fmap(
+    std::vector<std::pair<std::string, uint64_t>> history = utils::fmap(repl_storage_state.history);
-        [](const auto &elem) { return std::make_pair(elem.first, elem.second); }, repl_storage_state.history);
 
     history.emplace_back(std::string(repl_storage_state.epoch_.id()), repl_storage_state.last_commit_timestamp_.load());
     replication_coordination_glue::DatabaseHistory repl{

src/storage/v2/CMakeLists.txt

@@ -21,8 +21,10 @@ add_library(mg-storage-v2 STATIC
         storage.cpp
         indices/indices.cpp
         all_vertices_iterable.cpp
+        edges_iterable.cpp
         vertices_iterable.cpp
         inmemory/storage.cpp
+        inmemory/edge_type_index.cpp
         inmemory/label_index.cpp
         inmemory/label_property_index.cpp
         inmemory/unique_constraints.cpp
@@ -30,6 +32,7 @@ add_library(mg-storage-v2 STATIC
         disk/edge_import_mode_cache.cpp
         disk/storage.cpp
         disk/rocksdb_storage.cpp
+        disk/edge_type_index.cpp
         disk/label_index.cpp
         disk/label_property_index.cpp
         disk/unique_constraints.cpp

src/storage/v2/disk/edge_type_index.cpp

@@ -0,0 +1,49 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "edge_type_index.hpp"
+
+#include "utils/exceptions.hpp"
+
+namespace memgraph::storage {
+
+bool DiskEdgeTypeIndex::DropIndex(EdgeTypeId /*edge_type*/) {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return true;
+}
+
+bool DiskEdgeTypeIndex::IndexExists(EdgeTypeId /*edge_type*/) const {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return false;
+}
+
+std::vector<EdgeTypeId> DiskEdgeTypeIndex::ListIndices() const {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return {};
+}
+
+uint64_t DiskEdgeTypeIndex::ApproximateEdgeCount(EdgeTypeId /*edge_type*/) const {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return 0U;
+}
+
+void DiskEdgeTypeIndex::UpdateOnEdgeCreation(Vertex * /*from*/, Vertex * /*to*/, EdgeRef /*edge_ref*/,
+                                             EdgeTypeId /*edge_type*/, const Transaction & /*tx*/) {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+}
+
+void DiskEdgeTypeIndex::UpdateOnEdgeModification(Vertex * /*old_from*/, Vertex * /*old_to*/, Vertex * /*new_from*/,
+                                                 Vertex * /*new_to*/, EdgeRef /*edge_ref*/, EdgeTypeId /*edge_type*/,
+                                                 const Transaction & /*tx*/) {
+  spdlog::warn("Edge-type index related operations are not yet supported using on-disk storage mode.");
+}
+
+}  // namespace memgraph::storage

src/storage/v2/disk/edge_type_index.hpp

@@ -0,0 +1,35 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include "storage/v2/indices/edge_type_index.hpp"
+
+namespace memgraph::storage {
+
+class DiskEdgeTypeIndex : public storage::EdgeTypeIndex {
+ public:
+  bool DropIndex(EdgeTypeId edge_type) override;
+
+  bool IndexExists(EdgeTypeId edge_type) const override;
+
+  std::vector<EdgeTypeId> ListIndices() const override;
+
+  uint64_t ApproximateEdgeCount(EdgeTypeId edge_type) const override;
+
+  void UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                            const Transaction &tx) override;
+
+  void UpdateOnEdgeModification(Vertex *old_from, Vertex *old_to, Vertex *new_from, Vertex *new_to, EdgeRef edge_ref,
+                                EdgeTypeId edge_type, const Transaction &tx) override;
+};
+
+}  // namespace memgraph::storage

src/storage/v2/disk/storage.cpp

@@ -41,6 +41,7 @@
 #include "storage/v2/edge_accessor.hpp"
 #include "storage/v2/edge_import_mode.hpp"
 #include "storage/v2/edge_ref.hpp"
+#include "storage/v2/edges_iterable.hpp"
 #include "storage/v2/id_types.hpp"
 #include "storage/v2/modified_edge.hpp"
 #include "storage/v2/mvcc.hpp"
@@ -807,11 +808,21 @@ void DiskStorage::LoadVerticesFromDiskLabelPropertyIndexForIntervalSearch(
   }
 }
 
+EdgesIterable DiskStorage::DiskAccessor::Edges(EdgeTypeId /*edge_type*/, View /*view*/) {
+  throw utils::NotYetImplemented(
+      "Edge-type index related operations are not yet supported using on-disk storage mode.");
+}
+
 uint64_t DiskStorage::DiskAccessor::ApproximateVertexCount() const {
   auto *disk_storage = static_cast<DiskStorage *>(storage_);
   return disk_storage->vertex_count_.load(std::memory_order_acquire);
 }
 
+uint64_t DiskStorage::DiskAccessor::ApproximateEdgeCount(EdgeTypeId /*edge_type*/) const {
+  spdlog::info("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return 0U;
+}
+
 uint64_t DiskStorage::GetDiskSpaceUsage() const {
   uint64_t main_disk_storage_size = utils::GetDirDiskUsage(config_.disk.main_storage_directory);
   uint64_t index_disk_storage_size = utils::GetDirDiskUsage(config_.disk.label_index_directory) +
@@ -1629,6 +1640,9 @@ utils::BasicResult<StorageManipulationError, void> DiskStorage::DiskAccessor::Co
             return StorageManipulationError{PersistenceError{}};
           }
         } break;
+        case MetadataDelta::Action::EDGE_INDEX_CREATE: {
+          throw utils::NotYetImplemented("Edge-type indexing is not yet implemented on on-disk storage mode.");
+        }
         case MetadataDelta::Action::LABEL_INDEX_DROP: {
           if (!disk_storage->durable_metadata_.PersistLabelIndexDeletion(md_delta.label)) {
             return StorageManipulationError{PersistenceError{}};
@@ -1641,6 +1655,9 @@ utils::BasicResult<StorageManipulationError, void> DiskStorage::DiskAccessor::Co
             return StorageManipulationError{PersistenceError{}};
           }
         } break;
+        case MetadataDelta::Action::EDGE_INDEX_DROP: {
+          throw utils::NotYetImplemented("Edge-type indexing is not yet implemented on on-disk storage mode.");
+        }
         case MetadataDelta::Action::LABEL_INDEX_STATS_SET: {
           throw utils::NotYetImplemented("SetIndexStats(stats) is not implemented for DiskStorage.");
         } break;
@@ -1917,6 +1934,11 @@ utils::BasicResult<StorageIndexDefinitionError, void> DiskStorage::DiskAccessor:
   return {};
 }
 
+utils::BasicResult<StorageIndexDefinitionError, void> DiskStorage::DiskAccessor::CreateIndex(EdgeTypeId /*edge_type*/) {
+  throw utils::NotYetImplemented(
+      "Edge-type index related operations are not yet supported using on-disk storage mode.");
+}
+
 utils::BasicResult<StorageIndexDefinitionError, void> DiskStorage::DiskAccessor::DropIndex(LabelId label) {
   MG_ASSERT(unique_guard_.owns_lock(), "Create index requires a unique access to the storage!");
   auto *on_disk = static_cast<DiskStorage *>(storage_);
@@ -1945,6 +1967,11 @@ utils::BasicResult<StorageIndexDefinitionError, void> DiskStorage::DiskAccessor:
   return {};
 }
 
+utils::BasicResult<StorageIndexDefinitionError, void> DiskStorage::DiskAccessor::DropIndex(EdgeTypeId /*edge_type*/) {
+  throw utils::NotYetImplemented(
+      "Edge-type index related operations are not yet supported using on-disk storage mode.");
+}
+
 utils::BasicResult<StorageExistenceConstraintDefinitionError, void>
 DiskStorage::DiskAccessor::CreateExistenceConstraint(LabelId label, PropertyId property) {
   MG_ASSERT(unique_guard_.owns_lock(), "Create existence constraint requires a unique access to the storage!");
@@ -2053,6 +2080,12 @@ std::unique_ptr<Storage::Accessor> DiskStorage::UniqueAccess(
   return std::unique_ptr<DiskAccessor>(
       new DiskAccessor{Storage::Accessor::unique_access, this, isolation_level, storage_mode_});
 }
+
+bool DiskStorage::DiskAccessor::EdgeTypeIndexExists(EdgeTypeId /*edge_type*/) const {
+  spdlog::info("Edge-type index related operations are not yet supported using on-disk storage mode.");
+  return false;
+}
+
 IndicesInfo DiskStorage::DiskAccessor::ListAllIndices() const {
   auto *on_disk = static_cast<DiskStorage *>(storage_);
   auto *disk_label_index = static_cast<DiskLabelIndex *>(on_disk->indices_.label_index_.get());

src/storage/v2/disk/storage.hpp

@@ -72,6 +72,8 @@ class DiskStorage final : public Storage {
                               const std::optional<utils::Bound<PropertyValue>> &lower_bound,
                               const std::optional<utils::Bound<PropertyValue>> &upper_bound, View view) override;
 
+    EdgesIterable Edges(EdgeTypeId edge_type, View view) override;
+
     uint64_t ApproximateVertexCount() const override;
 
     uint64_t ApproximateVertexCount(LabelId /*label*/) const override { return 10; }
@@ -89,6 +91,8 @@ class DiskStorage final : public Storage {
       return 10;
     }
 
+    uint64_t ApproximateEdgeCount(EdgeTypeId edge_type) const override;
+
     std::optional<storage::LabelIndexStats> GetIndexStats(const storage::LabelId & /*label*/) const override {
       return {};
     }
@@ -140,6 +144,8 @@ class DiskStorage final : public Storage {
       return disk_storage->indices_.label_property_index_->IndexExists(label, property);
     }
 
+    bool EdgeTypeIndexExists(EdgeTypeId edge_type) const override;
+
     IndicesInfo ListAllIndices() const override;
 
     ConstraintsInfo ListAllConstraints() const override;
@@ -158,10 +164,14 @@ class DiskStorage final : public Storage {
 
     utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(LabelId label, PropertyId property) override;
 
+    utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(EdgeTypeId edge_type) override;
+
     utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(LabelId label) override;
 
     utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(LabelId label, PropertyId property) override;
 
+    utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(EdgeTypeId edge_type) override;
+
     utils::BasicResult<StorageExistenceConstraintDefinitionError, void> CreateExistenceConstraint(
         LabelId label, PropertyId property) override;
 

src/storage/v2/durability/durability.cpp

@@ -31,6 +31,7 @@
 #include "storage/v2/durability/paths.hpp"
 #include "storage/v2/durability/snapshot.hpp"
 #include "storage/v2/durability/wal.hpp"
+#include "storage/v2/inmemory/edge_type_index.hpp"
 #include "storage/v2/inmemory/label_index.hpp"
 #include "storage/v2/inmemory/label_property_index.hpp"
 #include "storage/v2/inmemory/unique_constraints.hpp"
@@ -199,9 +200,18 @@ void RecoverIndicesAndStats(const RecoveredIndicesAndConstraints::IndicesMetadat
   }
   spdlog::info("Label+property indices statistics are recreated.");
 
-  spdlog::info("Indices are recreated.");
+  // Recover edge-type indices.
+  spdlog::info("Recreating {} edge-type indices from metadata.", indices_metadata.edge.size());
+  auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(indices->edge_type_index_.get());
+  for (const auto &item : indices_metadata.edge) {
+    if (!mem_edge_type_index->CreateIndex(item, vertices->access())) {
+      throw RecoveryFailure("The edge-type index must be created here!");
+    }
+    spdlog::info("Index on :{} is recreated from metadata", name_id_mapper->IdToName(item.AsUint()));
+  }
+  spdlog::info("Edge-type indices are recreated.");
 
-  spdlog::info("Recreating constraints from metadata.");
+  spdlog::info("Indices are recreated.");
 }
 
 void RecoverExistenceConstraints(const RecoveredIndicesAndConstraints::ConstraintsMetadata &constraints_metadata,
@@ -358,7 +368,6 @@ std::optional<RecoveryInfo> Recovery::RecoverData(std::string *uuid, Replication
       spdlog::warn(utils::MessageWithLink("No snapshot or WAL file found.", "https://memgr.ph/durability"));
       return std::nullopt;
     }
-    // TODO(antoniofilipovic) What is the logic here?
     std::sort(wal_files.begin(), wal_files.end());
     // UUID used for durability is the UUID of the last WAL file.
     // Same for the epoch id.
@@ -437,17 +446,13 @@ std::optional<RecoveryInfo> Recovery::RecoverData(std::string *uuid, Replication
           last_loaded_timestamp.emplace(recovery_info.next_timestamp - 1);
         }
 
-        bool epoch_history_empty = epoch_history->empty();
-        bool epoch_not_recorded = !epoch_history_empty && epoch_history->back().first != wal_file.epoch_id;
         auto last_loaded_timestamp_value = last_loaded_timestamp.value_or(0);
-
+        if (epoch_history->empty() || epoch_history->back().first != wal_file.epoch_id) {
-        if (epoch_history_empty || epoch_not_recorded) {
+          // no history or new epoch, add it
-          epoch_history->emplace_back(std::string(wal_file.epoch_id), last_loaded_timestamp_value);
+          epoch_history->emplace_back(wal_file.epoch_id, last_loaded_timestamp_value);
-        }
+          repl_storage_state.epoch_.SetEpoch(wal_file.epoch_id);
-
+        } else if (epoch_history->back().second < last_loaded_timestamp_value) {
-        auto last_epoch_updated = !epoch_history_empty && epoch_history->back().first == wal_file.epoch_id &&
+          // existing epoch, update with newer timestamp
-                                  epoch_history->back().second < last_loaded_timestamp_value;
-        if (last_epoch_updated) {
           epoch_history->back().second = last_loaded_timestamp_value;
         }
 
@@ -469,11 +474,11 @@ std::optional<RecoveryInfo> Recovery::RecoverData(std::string *uuid, Replication
 
   memgraph::metrics::Measure(memgraph::metrics::SnapshotRecoveryLatency_us,
                              std::chrono::duration_cast<std::chrono::microseconds>(timer.Elapsed()).count());
-  spdlog::info("Set epoch id: {}  with commit timestamp {}", std::string(repl_storage_state.epoch_.id()),
+  spdlog::trace("Set epoch id: {}  with commit timestamp {}", std::string(repl_storage_state.epoch_.id()),
-               repl_storage_state.last_commit_timestamp_);
+                repl_storage_state.last_commit_timestamp_);
 
   std::for_each(repl_storage_state.history.begin(), repl_storage_state.history.end(), [](auto &history) {
-    spdlog::info("epoch id: {}  with commit timestamp {}", std::string(history.first), history.second);
+    spdlog::trace("epoch id: {}  with commit timestamp {}", std::string(history.first), history.second);
   });
   return recovery_info;
 }

src/storage/v2/durability/marker.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -37,6 +37,8 @@ enum class Marker : uint8_t {
   SECTION_CONSTRAINTS = 0x25,
   SECTION_DELTA = 0x26,
   SECTION_EPOCH_HISTORY = 0x27,
+  SECTION_EDGE_INDICES = 0x28,
+
   SECTION_OFFSETS = 0x42,
 
   DELTA_VERTEX_CREATE = 0x50,
@@ -60,6 +62,8 @@ enum class Marker : uint8_t {
   DELTA_LABEL_INDEX_STATS_CLEAR = 0x62,
   DELTA_LABEL_PROPERTY_INDEX_STATS_SET = 0x63,
   DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR = 0x64,
+  DELTA_EDGE_TYPE_INDEX_CREATE = 0x65,
+  DELTA_EDGE_TYPE_INDEX_DROP = 0x66,
 
   VALUE_FALSE = 0x00,
   VALUE_TRUE = 0xff,
@@ -85,6 +89,7 @@ static const Marker kMarkersAll[] = {
     Marker::SECTION_CONSTRAINTS,
     Marker::SECTION_DELTA,
     Marker::SECTION_EPOCH_HISTORY,
+    Marker::SECTION_EDGE_INDICES,
     Marker::SECTION_OFFSETS,
     Marker::DELTA_VERTEX_CREATE,
     Marker::DELTA_VERTEX_DELETE,
@@ -103,6 +108,8 @@ static const Marker kMarkersAll[] = {
     Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR,
     Marker::DELTA_LABEL_PROPERTY_INDEX_CREATE,
     Marker::DELTA_LABEL_PROPERTY_INDEX_DROP,
+    Marker::DELTA_EDGE_TYPE_INDEX_CREATE,
+    Marker::DELTA_EDGE_TYPE_INDEX_DROP,
     Marker::DELTA_EXISTENCE_CONSTRAINT_CREATE,
     Marker::DELTA_EXISTENCE_CONSTRAINT_DROP,
     Marker::DELTA_UNIQUE_CONSTRAINT_CREATE,

src/storage/v2/durability/metadata.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -43,6 +43,7 @@ struct RecoveredIndicesAndConstraints {
     std::vector<std::pair<LabelId, PropertyId>> label_property;
     std::vector<std::pair<LabelId, LabelIndexStats>> label_stats;
     std::vector<std::pair<LabelId, std::pair<PropertyId, LabelPropertyIndexStats>>> label_property_stats;
+    std::vector<EdgeTypeId> edge;
   } indices;
 
   struct ConstraintsMetadata {

src/storage/v2/durability/serialization.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -332,6 +332,7 @@ std::optional<PropertyValue> Decoder::ReadPropertyValue() {
     case Marker::SECTION_CONSTRAINTS:
     case Marker::SECTION_DELTA:
     case Marker::SECTION_EPOCH_HISTORY:
+    case Marker::SECTION_EDGE_INDICES:
     case Marker::SECTION_OFFSETS:
     case Marker::DELTA_VERTEX_CREATE:
     case Marker::DELTA_VERTEX_DELETE:
@@ -350,6 +351,8 @@ std::optional<PropertyValue> Decoder::ReadPropertyValue() {
     case Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR:
     case Marker::DELTA_LABEL_PROPERTY_INDEX_CREATE:
     case Marker::DELTA_LABEL_PROPERTY_INDEX_DROP:
+    case Marker::DELTA_EDGE_TYPE_INDEX_CREATE:
+    case Marker::DELTA_EDGE_TYPE_INDEX_DROP:
     case Marker::DELTA_EXISTENCE_CONSTRAINT_CREATE:
     case Marker::DELTA_EXISTENCE_CONSTRAINT_DROP:
     case Marker::DELTA_UNIQUE_CONSTRAINT_CREATE:
@@ -435,6 +438,7 @@ bool Decoder::SkipPropertyValue() {
     case Marker::SECTION_CONSTRAINTS:
     case Marker::SECTION_DELTA:
     case Marker::SECTION_EPOCH_HISTORY:
+    case Marker::SECTION_EDGE_INDICES:
     case Marker::SECTION_OFFSETS:
     case Marker::DELTA_VERTEX_CREATE:
     case Marker::DELTA_VERTEX_DELETE:
@@ -453,6 +457,8 @@ bool Decoder::SkipPropertyValue() {
     case Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR:
     case Marker::DELTA_LABEL_PROPERTY_INDEX_CREATE:
     case Marker::DELTA_LABEL_PROPERTY_INDEX_DROP:
+    case Marker::DELTA_EDGE_TYPE_INDEX_CREATE:
+    case Marker::DELTA_EDGE_TYPE_INDEX_DROP:
     case Marker::DELTA_EXISTENCE_CONSTRAINT_CREATE:
     case Marker::DELTA_EXISTENCE_CONSTRAINT_DROP:
     case Marker::DELTA_UNIQUE_CONSTRAINT_CREATE:

src/storage/v2/durability/snapshot.cpp

@@ -153,6 +153,11 @@ SnapshotInfo ReadSnapshotInfo(const std::filesystem::path &path) {
     info.offset_edges = read_offset();
     info.offset_vertices = read_offset();
     info.offset_indices = read_offset();
+    if (*version >= 17) {
+      info.offset_edge_indices = read_offset();
+    } else {
+      info.offset_edge_indices = 0U;
+    }
     info.offset_constraints = read_offset();
     info.offset_mapper = read_offset();
     info.offset_epoch_history = read_offset();
@@ -1379,10 +1384,11 @@ RecoveredSnapshot LoadSnapshotVersion15(const std::filesystem::path &path, utils
   return {info, recovery_info, std::move(indices_constraints)};
 }
 
-RecoveredSnapshot LoadSnapshot(const std::filesystem::path &path, utils::SkipList<Vertex> *vertices,
+RecoveredSnapshot LoadSnapshotVersion16(const std::filesystem::path &path, utils::SkipList<Vertex> *vertices,
-                               utils::SkipList<Edge> *edges,
+                                        utils::SkipList<Edge> *edges,
-                               std::deque<std::pair<std::string, uint64_t>> *epoch_history,
+                                        std::deque<std::pair<std::string, uint64_t>> *epoch_history,
-                               NameIdMapper *name_id_mapper, std::atomic<uint64_t> *edge_count, const Config &config) {
+                                        NameIdMapper *name_id_mapper, std::atomic<uint64_t> *edge_count,
+                                        const Config &config) {
   RecoveryInfo recovery_info;
   RecoveredIndicesAndConstraints indices_constraints;
 
@@ -1391,13 +1397,7 @@ RecoveredSnapshot LoadSnapshot(const std::filesystem::path &path, utils::SkipLis
   if (!version) throw RecoveryFailure("Couldn't read snapshot magic and/or version!");
 
   if (!IsVersionSupported(*version)) throw RecoveryFailure(fmt::format("Invalid snapshot version {}", *version));
-  if (*version == 14U) {
+  if (*version != 16U) throw RecoveryFailure(fmt::format("Expected snapshot version is 16, but got {}", *version));
-    return LoadSnapshotVersion14(path, vertices, edges, epoch_history, name_id_mapper, edge_count,
-                                 config.salient.items);
-  }
-  if (*version == 15U) {
-    return LoadSnapshotVersion15(path, vertices, edges, epoch_history, name_id_mapper, edge_count, config);
-  }
 
   // Cleanup of loaded data in case of failure.
   bool success = false;
@@ -1727,6 +1727,380 @@ RecoveredSnapshot LoadSnapshot(const std::filesystem::path &path, utils::SkipLis
   return {info, recovery_info, std::move(indices_constraints)};
 }
 
+RecoveredSnapshot LoadSnapshot(const std::filesystem::path &path, utils::SkipList<Vertex> *vertices,
+                               utils::SkipList<Edge> *edges,
+                               std::deque<std::pair<std::string, uint64_t>> *epoch_history,
+                               NameIdMapper *name_id_mapper, std::atomic<uint64_t> *edge_count, const Config &config) {
+  RecoveryInfo recovery_info;
+  RecoveredIndicesAndConstraints indices_constraints;
+
+  Decoder snapshot;
+  const auto version = snapshot.Initialize(path, kSnapshotMagic);
+  if (!version) throw RecoveryFailure("Couldn't read snapshot magic and/or version!");
+
+  if (!IsVersionSupported(*version)) throw RecoveryFailure(fmt::format("Invalid snapshot version {}", *version));
+  if (*version == 14U) {
+    return LoadSnapshotVersion14(path, vertices, edges, epoch_history, name_id_mapper, edge_count,
+                                 config.salient.items);
+  }
+  if (*version == 15U) {
+    return LoadSnapshotVersion15(path, vertices, edges, epoch_history, name_id_mapper, edge_count, config);
+  }
+  if (*version == 16U) {
+    return LoadSnapshotVersion16(path, vertices, edges, epoch_history, name_id_mapper, edge_count, config);
+  }
+
+  // Cleanup of loaded data in case of failure.
+  bool success = false;
+  utils::OnScopeExit cleanup([&] {
+    if (!success) {
+      edges->clear();
+      vertices->clear();
+      epoch_history->clear();
+    }
+  });
+
+  // Read snapshot info.
+  const auto info = ReadSnapshotInfo(path);
+  spdlog::info("Recovering {} vertices and {} edges.", info.vertices_count, info.edges_count);
+  // Check for edges.
+  bool snapshot_has_edges = info.offset_edges != 0;
+
+  // Recover mapper.
+  std::unordered_map<uint64_t, uint64_t> snapshot_id_map;
+  {
+    spdlog::info("Recovering mapper metadata.");
+    if (!snapshot.SetPosition(info.offset_mapper)) throw RecoveryFailure("Couldn't read data from snapshot!");
+
+    auto marker = snapshot.ReadMarker();
+    if (!marker || *marker != Marker::SECTION_MAPPER) throw RecoveryFailure("Failed to read section mapper!");
+
+    auto size = snapshot.ReadUint();
+    if (!size) throw RecoveryFailure("Failed to read name-id mapper size!");
+
+    for (uint64_t i = 0; i < *size; ++i) {
+      auto id = snapshot.ReadUint();
+      if (!id) throw RecoveryFailure("Failed to read id for name-id mapper!");
+      auto name = snapshot.ReadString();
+      if (!name) throw RecoveryFailure("Failed to read name for name-id mapper!");
+      auto my_id = name_id_mapper->NameToId(*name);
+      snapshot_id_map.emplace(*id, my_id);
+      SPDLOG_TRACE("Mapping \"{}\"from snapshot id {} to actual id {}.", *name, *id, my_id);
+    }
+  }
+  auto get_label_from_id = [&snapshot_id_map](uint64_t label_id) {
+    auto it = snapshot_id_map.find(label_id);
+    if (it == snapshot_id_map.end()) throw RecoveryFailure("Couldn't find label id in snapshot_id_map!");
+    return LabelId::FromUint(it->second);
+  };
+  auto get_property_from_id = [&snapshot_id_map](uint64_t property_id) {
+    auto it = snapshot_id_map.find(property_id);
+    if (it == snapshot_id_map.end()) throw RecoveryFailure("Couldn't find property id in snapshot_id_map!");
+    return PropertyId::FromUint(it->second);
+  };
+  auto get_edge_type_from_id = [&snapshot_id_map](uint64_t edge_type_id) {
+    auto it = snapshot_id_map.find(edge_type_id);
+    if (it == snapshot_id_map.end()) throw RecoveryFailure("Couldn't find edge type id in snapshot_id_map!");
+    return EdgeTypeId::FromUint(it->second);
+  };
+
+  // Reset current edge count.
+  edge_count->store(0, std::memory_order_release);
+
+  {
+    spdlog::info("Recovering edges.");
+    // Recover edges.
+    if (snapshot_has_edges) {
+      // We don't need to check whether we store properties on edge or not, because `LoadPartialEdges` will always
+      // iterate over the edges in the snapshot (if they exist) and the current configuration of properties on edge only
+      // affect what it does:
+      // 1. If properties are allowed on edges, then it loads the edges.
+      // 2. If properties are not allowed on edges, then it checks that none of the edges have any properties.
+      if (!snapshot.SetPosition(info.offset_edge_batches)) {
+        throw RecoveryFailure("Couldn't read data from snapshot!");
+      }
+      const auto edge_batches = ReadBatchInfos(snapshot);
+
+      RecoverOnMultipleThreads(
+          config.durability.recovery_thread_count,
+          [path, edges, items = config.salient.items, &get_property_from_id](const size_t /*batch_index*/,
+                                                                             const BatchInfo &batch) {
+            LoadPartialEdges(path, *edges, batch.offset, batch.count, items, get_property_from_id);
+          },
+          edge_batches);
+    }
+    spdlog::info("Edges are recovered.");
+
+    // Recover vertices (labels and properties).
+    spdlog::info("Recovering vertices.", info.vertices_count);
+    uint64_t last_vertex_gid{0};
+
+    if (!snapshot.SetPosition(info.offset_vertex_batches)) {
+      throw RecoveryFailure("Couldn't read data from snapshot!");
+    }
+
+    const auto vertex_batches = ReadBatchInfos(snapshot);
+    RecoverOnMultipleThreads(
+        config.durability.recovery_thread_count,
+        [path, vertices, &vertex_batches, &get_label_from_id, &get_property_from_id, &last_vertex_gid](
+            const size_t batch_index, const BatchInfo &batch) {
+          const auto last_vertex_gid_in_batch =
+              LoadPartialVertices(path, *vertices, batch.offset, batch.count, get_label_from_id, get_property_from_id);
+          if (batch_index == vertex_batches.size() - 1) {
+            last_vertex_gid = last_vertex_gid_in_batch;
+          }
+        },
+        vertex_batches);
+
+    spdlog::info("Vertices are recovered.");
+
+    // Recover vertices (in/out edges).
+    spdlog::info("Recover connectivity.");
+    recovery_info.vertex_batches.reserve(vertex_batches.size());
+    for (const auto batch : vertex_batches) {
+      recovery_info.vertex_batches.emplace_back(Gid::FromUint(0), batch.count);
+    }
+    std::atomic<uint64_t> highest_edge_gid{0};
+
+    RecoverOnMultipleThreads(
+        config.durability.recovery_thread_count,
+        [path, vertices, edges, edge_count, items = config.salient.items, snapshot_has_edges, &get_edge_type_from_id,
+         &highest_edge_gid, &recovery_info](const size_t batch_index, const BatchInfo &batch) {
+          const auto result = LoadPartialConnectivity(path, *vertices, *edges, batch.offset, batch.count, items,
+                                                      snapshot_has_edges, get_edge_type_from_id);
+          edge_count->fetch_add(result.edge_count);
+          auto known_highest_edge_gid = highest_edge_gid.load();
+          while (known_highest_edge_gid < result.highest_edge_id) {
+            highest_edge_gid.compare_exchange_weak(known_highest_edge_gid, result.highest_edge_id);
+          }
+          recovery_info.vertex_batches[batch_index].first = result.first_vertex_gid;
+        },
+        vertex_batches);
+
+    spdlog::info("Connectivity is recovered.");
+
+    // Set initial values for edge/vertex ID generators.
+    recovery_info.next_edge_id = highest_edge_gid + 1;
+    recovery_info.next_vertex_id = last_vertex_gid + 1;
+  }
+
+  // Recover indices.
+  {
+    spdlog::info("Recovering metadata of indices.");
+    if (!snapshot.SetPosition(info.offset_indices)) throw RecoveryFailure("Couldn't read data from snapshot!");
+
+    auto marker = snapshot.ReadMarker();
+    if (!marker || *marker != Marker::SECTION_INDICES) throw RecoveryFailure("Couldn't read section indices!");
+
+    // Recover label indices.
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't read the number of label indices");
+      spdlog::info("Recovering metadata of {} label indices.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label of label index!");
+        AddRecoveredIndexConstraint(&indices_constraints.indices.label, get_label_from_id(*label),
+                                    "The label index already exists!");
+        SPDLOG_TRACE("Recovered metadata of label index for :{}", name_id_mapper->IdToName(snapshot_id_map.at(*label)));
+      }
+      spdlog::info("Metadata of label indices are recovered.");
+    }
+
+    // Recover label indices statistics.
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't read the number of entries for label index statistics!");
+      spdlog::info("Recovering metadata of {} label indices statistics.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        const auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label while recovering label index statistics!");
+        const auto count = snapshot.ReadUint();
+        if (!count) throw RecoveryFailure("Couldn't read count for label index statistics!");
+        const auto avg_degree = snapshot.ReadDouble();
+        if (!avg_degree) throw RecoveryFailure("Couldn't read average degree for label index statistics");
+        const auto label_id = get_label_from_id(*label);
+        indices_constraints.indices.label_stats.emplace_back(label_id, LabelIndexStats{*count, *avg_degree});
+        SPDLOG_TRACE("Recovered metadata of label index statistics for :{}",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*label)));
+      }
+      spdlog::info("Metadata of label indices are recovered.");
+    }
+
+    // Recover label+property indices.
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't recover the number of label property indices!");
+      spdlog::info("Recovering metadata of {} label+property indices.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label for label property index!");
+        auto property = snapshot.ReadUint();
+        if (!property) throw RecoveryFailure("Couldn't read property for label property index");
+        AddRecoveredIndexConstraint(&indices_constraints.indices.label_property,
+                                    {get_label_from_id(*label), get_property_from_id(*property)},
+                                    "The label+property index already exists!");
+        SPDLOG_TRACE("Recovered metadata of label+property index for :{}({})",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*label)),
+                     name_id_mapper->IdToName(snapshot_id_map.at(*property)));
+      }
+      spdlog::info("Metadata of label+property indices are recovered.");
+    }
+
+    // Recover label+property indices statistics.
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't recover the number of entries for label property statistics!");
+      spdlog::info("Recovering metadata of {} label+property indices statistics.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        const auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label for label property index statistics!");
+        const auto property = snapshot.ReadUint();
+        if (!property) throw RecoveryFailure("Couldn't read property for label property index statistics!");
+        const auto count = snapshot.ReadUint();
+        if (!count) throw RecoveryFailure("Couldn't read count for label property index statistics!!");
+        const auto distinct_values_count = snapshot.ReadUint();
+        if (!distinct_values_count)
+          throw RecoveryFailure("Couldn't read distinct values count for label property index statistics!");
+        const auto statistic = snapshot.ReadDouble();
+        if (!statistic) throw RecoveryFailure("Couldn't read statistics value for label-property index statistics!");
+        const auto avg_group_size = snapshot.ReadDouble();
+        if (!avg_group_size)
+          throw RecoveryFailure("Couldn't read average group size for label property index statistics!");
+        const auto avg_degree = snapshot.ReadDouble();
+        if (!avg_degree) throw RecoveryFailure("Couldn't read average degree for label property index statistics!");
+        const auto label_id = get_label_from_id(*label);
+        const auto property_id = get_property_from_id(*property);
+        indices_constraints.indices.label_property_stats.emplace_back(
+            label_id, std::make_pair(property_id, LabelPropertyIndexStats{*count, *distinct_values_count, *statistic,
+                                                                          *avg_group_size, *avg_degree}));
+        SPDLOG_TRACE("Recovered metadata of label+property index statistics for :{}({})",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*label)),
+                     name_id_mapper->IdToName(snapshot_id_map.at(*property)));
+      }
+      spdlog::info("Metadata of label+property indices are recovered.");
+    }
+
+    // Recover edge-type indices.
+    spdlog::info("Recovering metadata of indices.");
+    if (!snapshot.SetPosition(info.offset_edge_indices)) throw RecoveryFailure("Couldn't read data from snapshot!");
+
+    marker = snapshot.ReadMarker();
+    if (!marker || *marker != Marker::SECTION_EDGE_INDICES)
+      throw RecoveryFailure("Couldn't read section edge-indices!");
+
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't read the number of edge-type indices");
+      spdlog::info("Recovering metadata of {} edge-type indices.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        auto edge_type = snapshot.ReadUint();
+        if (!edge_type) throw RecoveryFailure("Couldn't read edge-type of edge-type index!");
+        AddRecoveredIndexConstraint(&indices_constraints.indices.edge, get_edge_type_from_id(*edge_type),
+                                    "The edge-type index already exists!");
+        SPDLOG_TRACE("Recovered metadata of edge-type index for :{}",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*edge_type)));
+      }
+      spdlog::info("Metadata of edge-type indices are recovered.");
+    }
+
+    spdlog::info("Metadata of indices are recovered.");
+  }
+
+  // Recover constraints.
+  {
+    spdlog::info("Recovering metadata of constraints.");
+    if (!snapshot.SetPosition(info.offset_constraints)) throw RecoveryFailure("Couldn't read data from snapshot!");
+
+    auto marker = snapshot.ReadMarker();
+    if (!marker || *marker != Marker::SECTION_CONSTRAINTS)
+      throw RecoveryFailure("Couldn't read section constraints marker!");
+
+    // Recover existence constraints.
+    {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't read the number of existence constraints!");
+      spdlog::info("Recovering metadata of {} existence constraints.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label of existence constraints!");
+        auto property = snapshot.ReadUint();
+        if (!property) throw RecoveryFailure("Couldn't read property of existence constraints!");
+        AddRecoveredIndexConstraint(&indices_constraints.constraints.existence,
+                                    {get_label_from_id(*label), get_property_from_id(*property)},
+                                    "The existence constraint already exists!");
+        SPDLOG_TRACE("Recovered metadata of existence constraint for :{}({})",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*label)),
+                     name_id_mapper->IdToName(snapshot_id_map.at(*property)));
+      }
+      spdlog::info("Metadata of existence constraints are recovered.");
+    }
+
+    // Recover unique constraints.
+    // Snapshot version should be checked since unique constraints were
+    // implemented in later versions of snapshot.
+    if (*version >= kUniqueConstraintVersion) {
+      auto size = snapshot.ReadUint();
+      if (!size) throw RecoveryFailure("Couldn't read the number of unique constraints!");
+      spdlog::info("Recovering metadata of {} unique constraints.", *size);
+      for (uint64_t i = 0; i < *size; ++i) {
+        auto label = snapshot.ReadUint();
+        if (!label) throw RecoveryFailure("Couldn't read label of unique constraints!");
+        auto properties_count = snapshot.ReadUint();
+        if (!properties_count) throw RecoveryFailure("Couldn't read the number of properties in unique constraint!");
+        std::set<PropertyId> properties;
+        for (uint64_t j = 0; j < *properties_count; ++j) {
+          auto property = snapshot.ReadUint();
+          if (!property) throw RecoveryFailure("Couldn't read property of unique constraint!");
+          properties.insert(get_property_from_id(*property));
+        }
+        AddRecoveredIndexConstraint(&indices_constraints.constraints.unique, {get_label_from_id(*label), properties},
+                                    "The unique constraint already exists!");
+        SPDLOG_TRACE("Recovered metadata of unique constraints for :{}",
+                     name_id_mapper->IdToName(snapshot_id_map.at(*label)));
+      }
+      spdlog::info("Metadata of unique constraints are recovered.");
+    }
+    spdlog::info("Metadata of constraints are recovered.");
+  }
+
+  spdlog::info("Recovering metadata.");
+  // Recover epoch history
+  {
+    if (!snapshot.SetPosition(info.offset_epoch_history)) throw RecoveryFailure("Couldn't read data from snapshot!");
+
+    const auto marker = snapshot.ReadMarker();
+    if (!marker || *marker != Marker::SECTION_EPOCH_HISTORY)
+      throw RecoveryFailure("Couldn't read section epoch history marker!");
+
+    const auto history_size = snapshot.ReadUint();
+    if (!history_size) {
+      throw RecoveryFailure("Couldn't read history size!");
+    }
+
+    for (int i = 0; i < *history_size; ++i) {
+      auto maybe_epoch_id = snapshot.ReadString();
+      if (!maybe_epoch_id) {
+        throw RecoveryFailure("Couldn't read maybe epoch id!");
+      }
+      const auto maybe_last_commit_timestamp = snapshot.ReadUint();
+      if (!maybe_last_commit_timestamp) {
+        throw RecoveryFailure("Couldn't read maybe last commit timestamp!");
+      }
+      epoch_history->emplace_back(std::move(*maybe_epoch_id), *maybe_last_commit_timestamp);
+    }
+  }
+
+  spdlog::info("Metadata recovered.");
+  // Recover timestamp.
+  recovery_info.next_timestamp = info.start_timestamp + 1;
+
+  // Set success flag (to disable cleanup).
+  success = true;
+
+  return {info, recovery_info, std::move(indices_constraints)};
+}
+
 using OldSnapshotFiles = std::vector<std::pair<uint64_t, std::filesystem::path>>;
 void EnsureNecessaryWalFilesExist(const std::filesystem::path &wal_directory, const std::string &uuid,
                                   OldSnapshotFiles old_snapshot_files, Transaction *transaction,
@@ -1835,6 +2209,7 @@ void CreateSnapshot(Storage *storage, Transaction *transaction, const std::files
   uint64_t offset_edges = 0;
   uint64_t offset_vertices = 0;
   uint64_t offset_indices = 0;
+  uint64_t offset_edge_indices = 0;
   uint64_t offset_constraints = 0;
   uint64_t offset_mapper = 0;
   uint64_t offset_metadata = 0;
@@ -1847,6 +2222,7 @@ void CreateSnapshot(Storage *storage, Transaction *transaction, const std::files
     snapshot.WriteUint(offset_edges);
     snapshot.WriteUint(offset_vertices);
     snapshot.WriteUint(offset_indices);
+    snapshot.WriteUint(offset_edge_indices);
     snapshot.WriteUint(offset_constraints);
     snapshot.WriteUint(offset_mapper);
     snapshot.WriteUint(offset_epoch_history);
@@ -2106,6 +2482,17 @@ void CreateSnapshot(Storage *storage, Transaction *transaction, const std::files
         snapshot.SetPosition(last_pos);
       }
     }
+
+    // Write edge-type indices.
+    offset_edge_indices = snapshot.GetPosition();
+    snapshot.WriteMarker(Marker::SECTION_EDGE_INDICES);
+    {
+      auto edge_type = storage->indices_.edge_type_index_->ListIndices();
+      snapshot.WriteUint(edge_type.size());
+      for (const auto &item : edge_type) {
+        write_mapping(item);
+      }
+    }
   }
 
   // Write constraints.
@@ -2196,6 +2583,7 @@ void CreateSnapshot(Storage *storage, Transaction *transaction, const std::files
     snapshot.WriteUint(offset_edges);
     snapshot.WriteUint(offset_vertices);
     snapshot.WriteUint(offset_indices);
+    snapshot.WriteUint(offset_edge_indices);
     snapshot.WriteUint(offset_constraints);
     snapshot.WriteUint(offset_mapper);
     snapshot.WriteUint(offset_epoch_history);

src/storage/v2/durability/snapshot.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -34,6 +34,7 @@ struct SnapshotInfo {
   uint64_t offset_edges;
   uint64_t offset_vertices;
   uint64_t offset_indices;
+  uint64_t offset_edge_indices;
   uint64_t offset_constraints;
   uint64_t offset_mapper;
   uint64_t offset_epoch_history;

src/storage/v2/durability/storage_global_operation.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -23,6 +23,8 @@ enum class StorageMetadataOperation {
   LABEL_PROPERTY_INDEX_DROP,
   LABEL_PROPERTY_INDEX_STATS_SET,
   LABEL_PROPERTY_INDEX_STATS_CLEAR,
+  EDGE_TYPE_INDEX_CREATE,
+  EDGE_TYPE_INDEX_DROP,
   EXISTENCE_CONSTRAINT_CREATE,
   EXISTENCE_CONSTRAINT_DROP,
   UNIQUE_CONSTRAINT_CREATE,

src/storage/v2/durability/version.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -20,7 +20,7 @@ namespace memgraph::storage::durability {
 // The current version of snapshot and WAL encoding / decoding.
 // IMPORTANT: Please bump this version for every snapshot and/or WAL format
 // change!!!
-const uint64_t kVersion{16};
+const uint64_t kVersion{17};
 
 const uint64_t kOldestSupportedVersion{14};
 const uint64_t kUniqueConstraintVersion{13};

src/storage/v2/durability/wal.cpp

@@ -95,6 +95,10 @@ Marker OperationToMarker(StorageMetadataOperation operation) {
       return Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_SET;
     case StorageMetadataOperation::LABEL_PROPERTY_INDEX_STATS_CLEAR:
       return Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR;
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_CREATE:
+      return Marker::DELTA_EDGE_TYPE_INDEX_CREATE;
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_DROP:
+      return Marker::DELTA_EDGE_TYPE_INDEX_DROP;
     case StorageMetadataOperation::EXISTENCE_CONSTRAINT_CREATE:
       return Marker::DELTA_EXISTENCE_CONSTRAINT_CREATE;
     case StorageMetadataOperation::EXISTENCE_CONSTRAINT_DROP:
@@ -172,6 +176,10 @@ WalDeltaData::Type MarkerToWalDeltaDataType(Marker marker) {
       return WalDeltaData::Type::LABEL_PROPERTY_INDEX_STATS_SET;
     case Marker::DELTA_LABEL_PROPERTY_INDEX_STATS_CLEAR:
       return WalDeltaData::Type::LABEL_PROPERTY_INDEX_STATS_CLEAR;
+    case Marker::DELTA_EDGE_TYPE_INDEX_CREATE:
+      return WalDeltaData::Type::EDGE_INDEX_CREATE;
+    case Marker::DELTA_EDGE_TYPE_INDEX_DROP:
+      return WalDeltaData::Type::EDGE_INDEX_DROP;
     case Marker::DELTA_EXISTENCE_CONSTRAINT_CREATE:
       return WalDeltaData::Type::EXISTENCE_CONSTRAINT_CREATE;
     case Marker::DELTA_EXISTENCE_CONSTRAINT_DROP:
@@ -198,6 +206,7 @@ WalDeltaData::Type MarkerToWalDeltaDataType(Marker marker) {
     case Marker::SECTION_CONSTRAINTS:
     case Marker::SECTION_DELTA:
     case Marker::SECTION_EPOCH_HISTORY:
+    case Marker::SECTION_EDGE_INDICES:
     case Marker::SECTION_OFFSETS:
     case Marker::VALUE_FALSE:
     case Marker::VALUE_TRUE:
@@ -280,6 +289,7 @@ WalDeltaData ReadSkipWalDeltaData(BaseDecoder *decoder) {
     }
     case WalDeltaData::Type::TRANSACTION_END:
       break;
+    // NOLINTNEXTLINE(bugprone-branch-clone)
     case WalDeltaData::Type::LABEL_INDEX_CREATE:
     case WalDeltaData::Type::LABEL_INDEX_DROP:
     case WalDeltaData::Type::LABEL_INDEX_STATS_CLEAR:
@@ -295,6 +305,17 @@ WalDeltaData ReadSkipWalDeltaData(BaseDecoder *decoder) {
       }
       break;
     }
+    case WalDeltaData::Type::EDGE_INDEX_CREATE:
+    case WalDeltaData::Type::EDGE_INDEX_DROP: {
+      if constexpr (read_data) {
+        auto edge_type = decoder->ReadString();
+        if (!edge_type) throw RecoveryFailure("Invalid WAL data!");
+        delta.operation_edge_type.edge_type = std::move(*edge_type);
+      } else {
+        if (!decoder->SkipString()) throw RecoveryFailure("Invalid WAL data!");
+      }
+      break;
+    }
     case WalDeltaData::Type::LABEL_INDEX_STATS_SET: {
       if constexpr (read_data) {
         auto label = decoder->ReadString();
@@ -522,6 +543,9 @@ bool operator==(const WalDeltaData &a, const WalDeltaData &b) {
     case WalDeltaData::Type::UNIQUE_CONSTRAINT_DROP:
       return a.operation_label_properties.label == b.operation_label_properties.label &&
              a.operation_label_properties.properties == b.operation_label_properties.properties;
+    case WalDeltaData::Type::EDGE_INDEX_CREATE:
+    case WalDeltaData::Type::EDGE_INDEX_DROP:
+      return a.operation_edge_type.edge_type == b.operation_edge_type.edge_type;
   }
 }
 bool operator!=(const WalDeltaData &a, const WalDeltaData &b) { return !(a == b); }
@@ -703,6 +727,37 @@ void EncodeOperation(BaseEncoder *encoder, NameIdMapper *name_id_mapper, Storage
       }
       break;
     }
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_CREATE:
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_DROP: {
+      MG_ASSERT(false, "Invalid function  call!");
+    }
+  }
+}
+
+void EncodeOperation(BaseEncoder *encoder, NameIdMapper *name_id_mapper, StorageMetadataOperation operation,
+                     EdgeTypeId edge_type, uint64_t timestamp) {
+  encoder->WriteMarker(Marker::SECTION_DELTA);
+  encoder->WriteUint(timestamp);
+  switch (operation) {
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_CREATE:
+    case StorageMetadataOperation::EDGE_TYPE_INDEX_DROP: {
+      encoder->WriteMarker(OperationToMarker(operation));
+      encoder->WriteString(name_id_mapper->IdToName(edge_type.AsUint()));
+      break;
+    }
+    case StorageMetadataOperation::LABEL_INDEX_CREATE:
+    case StorageMetadataOperation::LABEL_INDEX_DROP:
+    case StorageMetadataOperation::LABEL_INDEX_STATS_CLEAR:
+    case StorageMetadataOperation::LABEL_PROPERTY_INDEX_STATS_CLEAR:
+    case StorageMetadataOperation::LABEL_INDEX_STATS_SET:
+    case StorageMetadataOperation::LABEL_PROPERTY_INDEX_CREATE:
+    case StorageMetadataOperation::LABEL_PROPERTY_INDEX_DROP:
+    case StorageMetadataOperation::EXISTENCE_CONSTRAINT_CREATE:
+    case StorageMetadataOperation::EXISTENCE_CONSTRAINT_DROP:
+    case StorageMetadataOperation::LABEL_PROPERTY_INDEX_STATS_SET:
+    case StorageMetadataOperation::UNIQUE_CONSTRAINT_CREATE:
+    case StorageMetadataOperation::UNIQUE_CONSTRAINT_DROP:
+      MG_ASSERT(false, "Invalid function call!");
   }
 }
 
@@ -887,6 +942,18 @@ RecoveryInfo LoadWal(const std::filesystem::path &path, RecoveredIndicesAndConst
                                          "The label index doesn't exist!");
           break;
         }
+        case WalDeltaData::Type::EDGE_INDEX_CREATE: {
+          auto edge_type_id = EdgeTypeId::FromUint(name_id_mapper->NameToId(delta.operation_edge_type.edge_type));
+          AddRecoveredIndexConstraint(&indices_constraints->indices.edge, edge_type_id,
+                                      "The edge-type index already exists!");
+          break;
+        }
+        case WalDeltaData::Type::EDGE_INDEX_DROP: {
+          auto edge_type_id = EdgeTypeId::FromUint(name_id_mapper->NameToId(delta.operation_edge_type.edge_type));
+          RemoveRecoveredIndexConstraint(&indices_constraints->indices.edge, edge_type_id,
+                                         "The edge-type index doesn't exist!");
+          break;
+        }
         case WalDeltaData::Type::LABEL_INDEX_STATS_SET: {
           auto label_id = LabelId::FromUint(name_id_mapper->NameToId(delta.operation_label_stats.label));
           LabelIndexStats stats{};
@@ -1088,6 +1155,11 @@ void WalFile::AppendOperation(StorageMetadataOperation operation, LabelId label,
   UpdateStats(timestamp);
 }
 
+void WalFile::AppendOperation(StorageMetadataOperation operation, EdgeTypeId edge_type, uint64_t timestamp) {
+  EncodeOperation(&wal_, name_id_mapper_, operation, edge_type, timestamp);
+  UpdateStats(timestamp);
+}
+
 void WalFile::Sync() { wal_.Sync(); }
 
 uint64_t WalFile::GetSize() { return wal_.GetSize(); }

src/storage/v2/durability/wal.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -67,6 +67,8 @@ struct WalDeltaData {
     LABEL_PROPERTY_INDEX_DROP,
     LABEL_PROPERTY_INDEX_STATS_SET,
     LABEL_PROPERTY_INDEX_STATS_CLEAR,
+    EDGE_INDEX_CREATE,
+    EDGE_INDEX_DROP,
     EXISTENCE_CONSTRAINT_CREATE,
     EXISTENCE_CONSTRAINT_DROP,
     UNIQUE_CONSTRAINT_CREATE,
@@ -111,6 +113,10 @@ struct WalDeltaData {
     std::set<std::string, std::less<>> properties;
   } operation_label_properties;
 
+  struct {
+    std::string edge_type;
+  } operation_edge_type;
+
   struct {
     std::string label;
     std::string stats;
@@ -155,6 +161,8 @@ constexpr bool IsWalDeltaDataTypeTransactionEndVersion15(const WalDeltaData::Typ
     case WalDeltaData::Type::LABEL_PROPERTY_INDEX_DROP:
     case WalDeltaData::Type::LABEL_PROPERTY_INDEX_STATS_SET:
     case WalDeltaData::Type::LABEL_PROPERTY_INDEX_STATS_CLEAR:
+    case WalDeltaData::Type::EDGE_INDEX_CREATE:
+    case WalDeltaData::Type::EDGE_INDEX_DROP:
     case WalDeltaData::Type::EXISTENCE_CONSTRAINT_CREATE:
     case WalDeltaData::Type::EXISTENCE_CONSTRAINT_DROP:
     case WalDeltaData::Type::UNIQUE_CONSTRAINT_CREATE:
@@ -164,7 +172,7 @@ constexpr bool IsWalDeltaDataTypeTransactionEndVersion15(const WalDeltaData::Typ
 }
 
 constexpr bool IsWalDeltaDataTypeTransactionEnd(const WalDeltaData::Type type, const uint64_t version = kVersion) {
-  if (version < 16U) {
+  if (version < 17U) {
     return IsWalDeltaDataTypeTransactionEndVersion15(type);
   }
   // All deltas are now handled in a transactional scope
@@ -208,6 +216,9 @@ void EncodeOperation(BaseEncoder *encoder, NameIdMapper *name_id_mapper, Storage
                      LabelId label, const std::set<PropertyId> &properties, const LabelIndexStats &stats,
                      const LabelPropertyIndexStats &property_stats, uint64_t timestamp);
 
+void EncodeOperation(BaseEncoder *encoder, NameIdMapper *name_id_mapper, StorageMetadataOperation operation,
+                     EdgeTypeId edge_type, uint64_t timestamp);
+
 /// Function used to load the WAL data into the storage.
 /// @throw RecoveryFailure
 RecoveryInfo LoadWal(const std::filesystem::path &path, RecoveredIndicesAndConstraints *indices_constraints,
@@ -240,6 +251,8 @@ class WalFile {
   void AppendOperation(StorageMetadataOperation operation, LabelId label, const std::set<PropertyId> &properties,
                        const LabelIndexStats &stats, const LabelPropertyIndexStats &property_stats, uint64_t timestamp);
 
+  void AppendOperation(StorageMetadataOperation operation, EdgeTypeId edge_type, uint64_t timestamp);
+
   void Sync();
 
   uint64_t GetSize();

src/storage/v2/edges_iterable.cpp

@@ -0,0 +1,149 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "storage/v2/edges_iterable.hpp"
+
+namespace memgraph::storage {
+
+EdgesIterable::EdgesIterable(InMemoryEdgeTypeIndex::Iterable edges) : type_(Type::BY_EDGE_TYPE_IN_MEMORY) {
+  new (&in_memory_edges_by_edge_type_) InMemoryEdgeTypeIndex::Iterable(std::move(edges));
+}
+
+EdgesIterable::EdgesIterable(EdgesIterable &&other) noexcept : type_(other.type_) {
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          InMemoryEdgeTypeIndex::Iterable(std::move(other.in_memory_edges_by_edge_type_));
+      break;
+  }
+}
+
+EdgesIterable &EdgesIterable::operator=(EdgesIterable &&other) noexcept {
+  Destroy();
+  type_ = other.type_;
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          InMemoryEdgeTypeIndex::Iterable(std::move(other.in_memory_edges_by_edge_type_));
+      break;
+  }
+  return *this;
+}
+
+EdgesIterable::~EdgesIterable() { Destroy(); }
+
+void EdgesIterable::Destroy() noexcept {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      in_memory_edges_by_edge_type_.InMemoryEdgeTypeIndex::Iterable::~Iterable();
+      break;
+  }
+}
+
+EdgesIterable::Iterator EdgesIterable::begin() {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      return Iterator(in_memory_edges_by_edge_type_.begin());
+  }
+}
+
+EdgesIterable::Iterator EdgesIterable::end() {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      return Iterator(in_memory_edges_by_edge_type_.end());
+  }
+}
+
+EdgesIterable::Iterator::Iterator(InMemoryEdgeTypeIndex::Iterable::Iterator it) : type_(Type::BY_EDGE_TYPE_IN_MEMORY) {
+  // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
+  new (&in_memory_edges_by_edge_type_) InMemoryEdgeTypeIndex::Iterable::Iterator(std::move(it));
+}
+
+EdgesIterable::Iterator::Iterator(const EdgesIterable::Iterator &other) : type_(other.type_) {
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          InMemoryEdgeTypeIndex::Iterable::Iterator(other.in_memory_edges_by_edge_type_);
+      break;
+  }
+}
+
+// NOLINTNEXTLINE(cert-oop54-cpp)
+EdgesIterable::Iterator &EdgesIterable::Iterator::operator=(const EdgesIterable::Iterator &other) {
+  Destroy();
+  type_ = other.type_;
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          InMemoryEdgeTypeIndex::Iterable::Iterator(other.in_memory_edges_by_edge_type_);
+      break;
+  }
+  return *this;
+}
+
+EdgesIterable::Iterator::Iterator(EdgesIterable::Iterator &&other) noexcept : type_(other.type_) {
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
+          InMemoryEdgeTypeIndex::Iterable::Iterator(std::move(other.in_memory_edges_by_edge_type_));
+      break;
+  }
+}
+
+EdgesIterable::Iterator &EdgesIterable::Iterator::operator=(EdgesIterable::Iterator &&other) noexcept {
+  Destroy();
+  type_ = other.type_;
+  switch (other.type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      new (&in_memory_edges_by_edge_type_)
+          // NOLINTNEXTLINE(hicpp-move-const-arg,performance-move-const-arg)
+          InMemoryEdgeTypeIndex::Iterable::Iterator(std::move(other.in_memory_edges_by_edge_type_));
+      break;
+  }
+  return *this;
+}
+
+EdgesIterable::Iterator::~Iterator() { Destroy(); }
+
+void EdgesIterable::Iterator::Destroy() noexcept {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      in_memory_edges_by_edge_type_.InMemoryEdgeTypeIndex::Iterable::Iterator::~Iterator();
+      break;
+  }
+}
+
+EdgeAccessor const &EdgesIterable::Iterator::operator*() const {
+  switch (type_) {
+    ;
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      return *in_memory_edges_by_edge_type_;
+  }
+}
+
+EdgesIterable::Iterator &EdgesIterable::Iterator::operator++() {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      ++in_memory_edges_by_edge_type_;
+      break;
+  }
+  return *this;
+}
+
+bool EdgesIterable::Iterator::operator==(const Iterator &other) const {
+  switch (type_) {
+    case Type::BY_EDGE_TYPE_IN_MEMORY:
+      return in_memory_edges_by_edge_type_ == other.in_memory_edges_by_edge_type_;
+  }
+}
+
+}  // namespace memgraph::storage

src/storage/v2/edges_iterable.hpp

@@ -0,0 +1,73 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include "storage/v2/all_vertices_iterable.hpp"
+#include "storage/v2/inmemory/edge_type_index.hpp"
+
+namespace memgraph::storage {
+
+class InMemoryEdgeTypeIndex;
+
+class EdgesIterable final {
+  enum class Type { BY_EDGE_TYPE_IN_MEMORY };
+
+  Type type_;
+  union {
+    InMemoryEdgeTypeIndex::Iterable in_memory_edges_by_edge_type_;
+  };
+
+  void Destroy() noexcept;
+
+ public:
+  explicit EdgesIterable(InMemoryEdgeTypeIndex::Iterable);
+
+  EdgesIterable(const EdgesIterable &) = delete;
+  EdgesIterable &operator=(const EdgesIterable &) = delete;
+
+  EdgesIterable(EdgesIterable &&) noexcept;
+  EdgesIterable &operator=(EdgesIterable &&) noexcept;
+
+  ~EdgesIterable();
+
+  class Iterator final {
+    Type type_;
+    union {
+      InMemoryEdgeTypeIndex::Iterable::Iterator in_memory_edges_by_edge_type_;
+    };
+
+    void Destroy() noexcept;
+
+   public:
+    explicit Iterator(InMemoryEdgeTypeIndex::Iterable::Iterator);
+
+    Iterator(const Iterator &);
+    Iterator &operator=(const Iterator &);
+
+    Iterator(Iterator &&) noexcept;
+    Iterator &operator=(Iterator &&) noexcept;
+
+    ~Iterator();
+
+    EdgeAccessor const &operator*() const;
+
+    Iterator &operator++();
+
+    bool operator==(const Iterator &other) const;
+    bool operator!=(const Iterator &other) const { return !(*this == other); }
+  };
+
+  Iterator begin();
+  Iterator end();
+};
+
+}  // namespace memgraph::storage

src/storage/v2/indices/edge_type_index.hpp

@@ -0,0 +1,46 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include <vector>
+
+#include "storage/v2/transaction.hpp"
+
+namespace memgraph::storage {
+
+class EdgeTypeIndex {
+ public:
+  EdgeTypeIndex() = default;
+
+  EdgeTypeIndex(const EdgeTypeIndex &) = delete;
+  EdgeTypeIndex(EdgeTypeIndex &&) = delete;
+  EdgeTypeIndex &operator=(const EdgeTypeIndex &) = delete;
+  EdgeTypeIndex &operator=(EdgeTypeIndex &&) = delete;
+
+  virtual ~EdgeTypeIndex() = default;
+
+  virtual bool DropIndex(EdgeTypeId edge_type) = 0;
+
+  virtual bool IndexExists(EdgeTypeId edge_type) const = 0;
+
+  virtual std::vector<EdgeTypeId> ListIndices() const = 0;
+
+  virtual uint64_t ApproximateEdgeCount(EdgeTypeId edge_type) const = 0;
+
+  virtual void UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                                    const Transaction &tx) = 0;
+
+  virtual void UpdateOnEdgeModification(Vertex *old_from, Vertex *old_to, Vertex *new_from, Vertex *new_to,
+                                        EdgeRef edge_ref, EdgeTypeId edge_type, const Transaction &tx) = 0;
+};
+
+}  // namespace memgraph::storage

src/storage/v2/indices/indices.cpp

@@ -10,8 +10,10 @@
 // licenses/APL.txt.
 
 #include "storage/v2/indices/indices.hpp"
+#include "storage/v2/disk/edge_type_index.hpp"
 #include "storage/v2/disk/label_index.hpp"
 #include "storage/v2/disk/label_property_index.hpp"
+#include "storage/v2/inmemory/edge_type_index.hpp"
 #include "storage/v2/inmemory/label_index.hpp"
 #include "storage/v2/inmemory/label_property_index.hpp"
 
@@ -35,6 +37,8 @@ void Indices::AbortEntries(LabelId label, std::span<std::pair<PropertyValue, Ver
 void Indices::RemoveObsoleteEntries(uint64_t oldest_active_start_timestamp, std::stop_token token) const {
   static_cast<InMemoryLabelIndex *>(label_index_.get())->RemoveObsoleteEntries(oldest_active_start_timestamp, token);
   static_cast<InMemoryLabelPropertyIndex *>(label_property_index_.get())
+      ->RemoveObsoleteEntries(oldest_active_start_timestamp, token);
+  static_cast<InMemoryEdgeTypeIndex *>(edge_type_index_.get())
       ->RemoveObsoleteEntries(oldest_active_start_timestamp, std::move(token));
 }
 
@@ -53,14 +57,21 @@ void Indices::UpdateOnSetProperty(PropertyId property, const PropertyValue &valu
   label_property_index_->UpdateOnSetProperty(property, value, vertex, tx);
 }
 
+void Indices::UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                                   const Transaction &tx) const {
+  edge_type_index_->UpdateOnEdgeCreation(from, to, edge_ref, edge_type, tx);
+}
+
 Indices::Indices(const Config &config, StorageMode storage_mode) {
   std::invoke([this, config, storage_mode]() {
     if (storage_mode == StorageMode::IN_MEMORY_TRANSACTIONAL || storage_mode == StorageMode::IN_MEMORY_ANALYTICAL) {
       label_index_ = std::make_unique<InMemoryLabelIndex>();
       label_property_index_ = std::make_unique<InMemoryLabelPropertyIndex>();
+      edge_type_index_ = std::make_unique<InMemoryEdgeTypeIndex>();
     } else {
       label_index_ = std::make_unique<DiskLabelIndex>(config);
       label_property_index_ = std::make_unique<DiskLabelPropertyIndex>(config);
+      edge_type_index_ = std::make_unique<DiskEdgeTypeIndex>();
     }
   });
 }

src/storage/v2/indices/indices.hpp

@@ -15,6 +15,7 @@
 #include <span>
 
 #include "storage/v2/id_types.hpp"
+#include "storage/v2/indices/edge_type_index.hpp"
 #include "storage/v2/indices/label_index.hpp"
 #include "storage/v2/indices/label_property_index.hpp"
 #include "storage/v2/storage_mode.hpp"
@@ -64,8 +65,12 @@ struct Indices {
   void UpdateOnSetProperty(PropertyId property, const PropertyValue &value, Vertex *vertex,
                            const Transaction &tx) const;
 
+  void UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                            const Transaction &tx) const;
+
   std::unique_ptr<LabelIndex> label_index_;
   std::unique_ptr<LabelPropertyIndex> label_property_index_;
+  std::unique_ptr<EdgeTypeIndex> edge_type_index_;
 };
 
 }  // namespace memgraph::storage

src/storage/v2/inmemory/edge_type_index.cpp

@@ -0,0 +1,318 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#include "storage/v2/inmemory/edge_type_index.hpp"
+
+#include "storage/v2/constraints/constraints.hpp"
+#include "storage/v2/indices/indices_utils.hpp"
+#include "utils/counter.hpp"
+
+namespace {
+
+using Delta = memgraph::storage::Delta;
+using Vertex = memgraph::storage::Vertex;
+using Edge = memgraph::storage::Edge;
+using EdgeRef = memgraph::storage::EdgeRef;
+using EdgeTypeId = memgraph::storage::EdgeTypeId;
+using Transaction = memgraph::storage::Transaction;
+using View = memgraph::storage::View;
+
+bool IsIndexEntryVisible(Edge *edge, const Transaction *transaction, View view) {
+  bool exists = true;
+  bool deleted = true;
+  Delta *delta = nullptr;
+  {
+    auto guard = std::shared_lock{edge->lock};
+    deleted = edge->deleted;
+    delta = edge->delta;
+  }
+  ApplyDeltasForRead(transaction, delta, view, [&](const Delta &delta) {
+    switch (delta.action) {
+      case Delta::Action::ADD_LABEL:
+      case Delta::Action::REMOVE_LABEL:
+      case Delta::Action::SET_PROPERTY:
+      case Delta::Action::ADD_IN_EDGE:
+      case Delta::Action::ADD_OUT_EDGE:
+      case Delta::Action::REMOVE_IN_EDGE:
+      case Delta::Action::REMOVE_OUT_EDGE:
+        break;
+      case Delta::Action::RECREATE_OBJECT: {
+        deleted = false;
+        break;
+      }
+      case Delta::Action::DELETE_DESERIALIZED_OBJECT:
+      case Delta::Action::DELETE_OBJECT: {
+        exists = false;
+        break;
+      }
+    }
+  });
+  return exists && !deleted;
+}
+
+using ReturnType = std::optional<std::tuple<EdgeTypeId, Vertex *, EdgeRef>>;
+ReturnType VertexDeletedConnectedEdges(Vertex *vertex, Edge *edge, const Transaction *transaction, View view) {
+  ReturnType link;
+  Delta *delta = nullptr;
+  {
+    auto guard = std::shared_lock{vertex->lock};
+    delta = vertex->delta;
+  }
+  ApplyDeltasForRead(transaction, delta, view, [&](const Delta &delta) {
+    switch (delta.action) {
+      case Delta::Action::ADD_LABEL:
+      case Delta::Action::REMOVE_LABEL:
+      case Delta::Action::SET_PROPERTY:
+        break;
+      case Delta::Action::ADD_IN_EDGE: {
+        if (edge == delta.vertex_edge.edge.ptr) {
+          link = {delta.vertex_edge.edge_type, delta.vertex_edge.vertex, delta.vertex_edge.edge};
+          auto it = std::find(vertex->in_edges.begin(), vertex->in_edges.end(), link);
+          MG_ASSERT(it == vertex->in_edges.end(), "Invalid database state!");
+          break;
+        }
+      }
+      case Delta::Action::ADD_OUT_EDGE: {
+        if (edge == delta.vertex_edge.edge.ptr) {
+          link = {delta.vertex_edge.edge_type, delta.vertex_edge.vertex, delta.vertex_edge.edge};
+          auto it = std::find(vertex->out_edges.begin(), vertex->out_edges.end(), link);
+          MG_ASSERT(it == vertex->out_edges.end(), "Invalid database state!");
+          break;
+        }
+      }
+      case Delta::Action::REMOVE_IN_EDGE:
+      case Delta::Action::REMOVE_OUT_EDGE:
+      case Delta::Action::RECREATE_OBJECT:
+      case Delta::Action::DELETE_DESERIALIZED_OBJECT:
+      case Delta::Action::DELETE_OBJECT:
+        break;
+    }
+  });
+  return link;
+}
+
+}  // namespace
+
+namespace memgraph::storage {
+
+bool InMemoryEdgeTypeIndex::CreateIndex(EdgeTypeId edge_type, utils::SkipList<Vertex>::Accessor vertices) {
+  auto [it, emplaced] = index_.try_emplace(edge_type);
+  if (!emplaced) {
+    return false;
+  }
+
+  utils::MemoryTracker::OutOfMemoryExceptionEnabler oom_exception;
+  try {
+    auto edge_acc = it->second.access();
+    for (auto &from_vertex : vertices) {
+      if (from_vertex.deleted) {
+        continue;
+      }
+
+      for (auto &edge : from_vertex.out_edges) {
+        const auto type = std::get<kEdgeTypeIdPos>(edge);
+        if (type == edge_type) {
+          auto *to_vertex = std::get<kVertexPos>(edge);
+          if (to_vertex->deleted) {
+            continue;
+          }
+          edge_acc.insert({&from_vertex, to_vertex, std::get<kEdgeRefPos>(edge).ptr, 0});
+        }
+      }
+    }
+  } catch (const utils::OutOfMemoryException &) {
+    utils::MemoryTracker::OutOfMemoryExceptionBlocker oom_exception_blocker;
+    index_.erase(it);
+    throw;
+  }
+
+  return true;
+}
+
+bool InMemoryEdgeTypeIndex::DropIndex(EdgeTypeId edge_type) { return index_.erase(edge_type) > 0; }
+
+bool InMemoryEdgeTypeIndex::IndexExists(EdgeTypeId edge_type) const { return index_.find(edge_type) != index_.end(); }
+
+std::vector<EdgeTypeId> InMemoryEdgeTypeIndex::ListIndices() const {
+  std::vector<EdgeTypeId> ret;
+  ret.reserve(index_.size());
+  for (const auto &item : index_) {
+    ret.push_back(item.first);
+  }
+  return ret;
+}
+
+void InMemoryEdgeTypeIndex::RemoveObsoleteEntries(uint64_t oldest_active_start_timestamp, std::stop_token token) {
+  auto maybe_stop = utils::ResettableCounter<2048>();
+
+  for (auto &label_storage : index_) {
+    if (token.stop_requested()) return;
+
+    auto edges_acc = label_storage.second.access();
+    for (auto it = edges_acc.begin(); it != edges_acc.end();) {
+      if (maybe_stop() && token.stop_requested()) return;
+
+      auto next_it = it;
+      ++next_it;
+
+      if (it->timestamp >= oldest_active_start_timestamp) {
+        it = next_it;
+        continue;
+      }
+
+      if (next_it != edges_acc.end() || it->from_vertex->deleted || it->to_vertex->deleted ||
+          !std::ranges::all_of(it->from_vertex->out_edges, [&](const auto &edge) {
+            auto *to_vertex = std::get<InMemoryEdgeTypeIndex::kVertexPos>(edge);
+            return to_vertex != it->to_vertex;
+          })) {
+        edges_acc.remove(*it);
+      }
+
+      it = next_it;
+    }
+  }
+}
+
+uint64_t InMemoryEdgeTypeIndex::ApproximateEdgeCount(EdgeTypeId edge_type) const {
+  if (auto it = index_.find(edge_type); it != index_.end()) {
+    return it->second.size();
+  }
+  return 0;
+}
+
+void InMemoryEdgeTypeIndex::UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                                                 const Transaction &tx) {
+  auto it = index_.find(edge_type);
+  if (it == index_.end()) {
+    return;
+  }
+  auto acc = it->second.access();
+  acc.insert(Entry{from, to, edge_ref.ptr, tx.start_timestamp});
+}
+
+void InMemoryEdgeTypeIndex::UpdateOnEdgeModification(Vertex *old_from, Vertex *old_to, Vertex *new_from, Vertex *new_to,
+                                                     EdgeRef edge_ref, EdgeTypeId edge_type, const Transaction &tx) {
+  auto it = index_.find(edge_type);
+  if (it == index_.end()) {
+    return;
+  }
+  auto acc = it->second.access();
+
+  auto entry_to_update = std::ranges::find_if(acc, [&](const auto &entry) {
+    return entry.from_vertex == old_from && entry.to_vertex == old_to && entry.edge == edge_ref.ptr;
+  });
+
+  acc.remove(Entry{entry_to_update->from_vertex, entry_to_update->to_vertex, entry_to_update->edge,
+                   entry_to_update->timestamp});
+  acc.insert(Entry{new_from, new_to, edge_ref.ptr, tx.start_timestamp});
+}
+
+InMemoryEdgeTypeIndex::Iterable::Iterable(utils::SkipList<Entry>::Accessor index_accessor, EdgeTypeId edge_type,
+                                          View view, Storage *storage, Transaction *transaction)
+    : index_accessor_(std::move(index_accessor)),
+      edge_type_(edge_type),
+      view_(view),
+      storage_(storage),
+      transaction_(transaction) {}
+
+InMemoryEdgeTypeIndex::Iterable::Iterator::Iterator(Iterable *self, utils::SkipList<Entry>::Iterator index_iterator)
+    : self_(self),
+      index_iterator_(index_iterator),
+      current_edge_accessor_(EdgeRef{nullptr}, EdgeTypeId::FromInt(0), nullptr, nullptr, self_->storage_, nullptr),
+      current_edge_(nullptr) {
+  AdvanceUntilValid();
+}
+
+InMemoryEdgeTypeIndex::Iterable::Iterator &InMemoryEdgeTypeIndex::Iterable::Iterator::operator++() {
+  ++index_iterator_;
+  AdvanceUntilValid();
+  return *this;
+}
+
+void InMemoryEdgeTypeIndex::Iterable::Iterator::AdvanceUntilValid() {
+  for (; index_iterator_ != self_->index_accessor_.end(); ++index_iterator_) {
+    auto *from_vertex = index_iterator_->from_vertex;
+    auto *to_vertex = index_iterator_->to_vertex;
+
+    if (!IsIndexEntryVisible(index_iterator_->edge, self_->transaction_, self_->view_) || from_vertex->deleted ||
+        to_vertex->deleted) {
+      continue;
+    }
+
+    const bool edge_was_deleted = index_iterator_->edge->deleted;
+    auto [edge_ref, edge_type, deleted_from_vertex, deleted_to_vertex] = GetEdgeInfo();
+    MG_ASSERT(edge_ref != EdgeRef(nullptr), "Invalid database state!");
+
+    if (edge_was_deleted) {
+      from_vertex = deleted_from_vertex;
+      to_vertex = deleted_to_vertex;
+    }
+
+    auto accessor = EdgeAccessor{edge_ref, edge_type, from_vertex, to_vertex, self_->storage_, self_->transaction_};
+    if (!accessor.IsVisible(self_->view_)) {
+      continue;
+    }
+
+    current_edge_accessor_ = accessor;
+    current_edge_ = edge_ref;
+    break;
+  }
+}
+
+std::tuple<EdgeRef, EdgeTypeId, Vertex *, Vertex *> InMemoryEdgeTypeIndex::Iterable::Iterator::GetEdgeInfo() {
+  auto *from_vertex = index_iterator_->from_vertex;
+  auto *to_vertex = index_iterator_->to_vertex;
+
+  if (index_iterator_->edge->deleted) {
+    const auto missing_in_edge =
+        VertexDeletedConnectedEdges(from_vertex, index_iterator_->edge, self_->transaction_, self_->view_);
+    const auto missing_out_edge =
+        VertexDeletedConnectedEdges(to_vertex, index_iterator_->edge, self_->transaction_, self_->view_);
+    if (missing_in_edge && missing_out_edge &&
+        std::get<kEdgeRefPos>(*missing_in_edge) == std::get<kEdgeRefPos>(*missing_out_edge)) {
+      return std::make_tuple(std::get<kEdgeRefPos>(*missing_in_edge), std::get<kEdgeTypeIdPos>(*missing_in_edge),
+                             to_vertex, from_vertex);
+    }
+  }
+
+  const auto &from_edges = from_vertex->out_edges;
+  const auto &to_edges = to_vertex->in_edges;
+
+  auto it = std::find_if(from_edges.begin(), from_edges.end(), [&](const auto &from_entry) {
+    const auto &from_edge = std::get<kEdgeRefPos>(from_entry);
+    return std::any_of(to_edges.begin(), to_edges.end(), [&](const auto &to_entry) {
+      const auto &to_edge = std::get<kEdgeRefPos>(to_entry);
+      return index_iterator_->edge->gid == from_edge.ptr->gid && from_edge.ptr->gid == to_edge.ptr->gid;
+    });
+  });
+
+  if (it != from_edges.end()) {
+    const auto &from_edge = std::get<kEdgeRefPos>(*it);
+    return std::make_tuple(from_edge, std::get<kEdgeTypeIdPos>(*it), from_vertex, to_vertex);
+  }
+
+  return {EdgeRef(nullptr), EdgeTypeId::FromUint(0U), nullptr, nullptr};
+}
+
+void InMemoryEdgeTypeIndex::RunGC() {
+  for (auto &index_entry : index_) {
+    index_entry.second.run_gc();
+  }
+}
+
+InMemoryEdgeTypeIndex::Iterable InMemoryEdgeTypeIndex::Edges(EdgeTypeId edge_type, View view, Storage *storage,
+                                                             Transaction *transaction) {
+  const auto it = index_.find(edge_type);
+  MG_ASSERT(it != index_.end(), "Index for edge-type {} doesn't exist", edge_type.AsUint());
+  return {it->second.access(), edge_type, view, storage, transaction};
+}
+
+}  // namespace memgraph::storage

src/storage/v2/inmemory/edge_type_index.hpp

@@ -0,0 +1,113 @@
+// Copyright 2024 Memgraph Ltd.
+//
+// Use of this software is governed by the Business Source License
+// included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
+// License, and you may not use this file except in compliance with the Business Source License.
+//
+// As of the Change Date specified in that file, in accordance with
+// the Business Source License, use of this software will be governed
+// by the Apache License, Version 2.0, included in the file
+// licenses/APL.txt.
+
+#pragma once
+
+#include <map>
+#include <utility>
+
+#include "storage/v2/constraints/constraints.hpp"
+#include "storage/v2/edge_accessor.hpp"
+#include "storage/v2/id_types.hpp"
+#include "storage/v2/indices/edge_type_index.hpp"
+#include "storage/v2/indices/label_index_stats.hpp"
+#include "utils/rw_lock.hpp"
+#include "utils/synchronized.hpp"
+
+namespace memgraph::storage {
+
+class InMemoryEdgeTypeIndex : public storage::EdgeTypeIndex {
+ private:
+  struct Entry {
+    Vertex *from_vertex;
+    Vertex *to_vertex;
+
+    Edge *edge;
+
+    uint64_t timestamp;
+
+    bool operator<(const Entry &rhs) const { return edge->gid < rhs.edge->gid; }
+    bool operator==(const Entry &rhs) const { return edge->gid == rhs.edge->gid; }
+  };
+
+ public:
+  InMemoryEdgeTypeIndex() = default;
+
+  /// @throw std::bad_alloc
+  bool CreateIndex(EdgeTypeId edge_type, utils::SkipList<Vertex>::Accessor vertices);
+
+  /// Returns false if there was no index to drop
+  bool DropIndex(EdgeTypeId edge_type) override;
+
+  bool IndexExists(EdgeTypeId edge_type) const override;
+
+  std::vector<EdgeTypeId> ListIndices() const override;
+
+  void RemoveObsoleteEntries(uint64_t oldest_active_start_timestamp, std::stop_token token);
+
+  uint64_t ApproximateEdgeCount(EdgeTypeId edge_type) const override;
+
+  void UpdateOnEdgeCreation(Vertex *from, Vertex *to, EdgeRef edge_ref, EdgeTypeId edge_type,
+                            const Transaction &tx) override;
+
+  void UpdateOnEdgeModification(Vertex *old_from, Vertex *old_to, Vertex *new_from, Vertex *new_to, EdgeRef edge_ref,
+                                EdgeTypeId edge_type, const Transaction &tx) override;
+
+  static constexpr std::size_t kEdgeTypeIdPos = 0U;
+  static constexpr std::size_t kVertexPos = 1U;
+  static constexpr std::size_t kEdgeRefPos = 2U;
+
+  class Iterable {
+   public:
+    Iterable(utils::SkipList<Entry>::Accessor index_accessor, EdgeTypeId edge_type, View view, Storage *storage,
+             Transaction *transaction);
+
+    class Iterator {
+     public:
+      Iterator(Iterable *self, utils::SkipList<Entry>::Iterator index_iterator);
+
+      EdgeAccessor const &operator*() const { return current_edge_accessor_; }
+
+      bool operator==(const Iterator &other) const { return index_iterator_ == other.index_iterator_; }
+      bool operator!=(const Iterator &other) const { return index_iterator_ != other.index_iterator_; }
+
+      Iterator &operator++();
+
+     private:
+      void AdvanceUntilValid();
+      std::tuple<EdgeRef, EdgeTypeId, Vertex *, Vertex *> GetEdgeInfo();
+
+      Iterable *self_;
+      utils::SkipList<Entry>::Iterator index_iterator_;
+      EdgeAccessor current_edge_accessor_;
+      EdgeRef current_edge_{nullptr};
+    };
+
+    Iterator begin() { return {this, index_accessor_.begin()}; }
+    Iterator end() { return {this, index_accessor_.end()}; }
+
+   private:
+    utils::SkipList<Entry>::Accessor index_accessor_;
+    EdgeTypeId edge_type_;
+    View view_;
+    Storage *storage_;
+    Transaction *transaction_;
+  };
+
+  void RunGC();
+
+  Iterable Edges(EdgeTypeId edge_type, View view, Storage *storage, Transaction *transaction);
+
+ private:
+  std::map<EdgeTypeId, utils::SkipList<Entry>> index_;
+};
+
+}  // namespace memgraph::storage

src/storage/v2/inmemory/storage.cpp

@@ -20,6 +20,7 @@
 #include "storage/v2/durability/snapshot.hpp"
 #include "storage/v2/edge_direction.hpp"
 #include "storage/v2/id_types.hpp"
+#include "storage/v2/inmemory/edge_type_index.hpp"
 #include "storage/v2/metadata_delta.hpp"
 
 /// REPLICATION ///
@@ -109,7 +110,7 @@ InMemoryStorage::InMemoryStorage(Config config)
       timestamp_ = std::max(timestamp_, info->next_timestamp);
       if (info->last_commit_timestamp) {
         repl_storage_state_.last_commit_timestamp_ = *info->last_commit_timestamp;
-        spdlog::info("Recovering last commit timestamp {}", *info->last_commit_timestamp);
+        spdlog::trace("Recovering last commit timestamp {}", *info->last_commit_timestamp);
       }
     }
   } else if (config_.durability.snapshot_wal_mode != Config::Durability::SnapshotWalMode::DISABLED ||
@@ -350,6 +351,9 @@ Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::CreateEdge(VertexAccesso
         transaction_.manyDeltasCache.Invalidate(from_vertex, edge_type, EdgeDirection::OUT);
         transaction_.manyDeltasCache.Invalidate(to_vertex, edge_type, EdgeDirection::IN);
 
+        // Update indices if they exist.
+        storage_->indices_.UpdateOnEdgeCreation(from_vertex, to_vertex, edge, edge_type, transaction_);
+
         // Increment edge count.
         storage_->edge_count_.fetch_add(1, std::memory_order_acq_rel);
       }};
@@ -553,6 +557,11 @@ Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::EdgeSetFrom(EdgeAccessor
         CreateAndLinkDelta(&transaction_, to_vertex, Delta::RemoveInEdgeTag(), edge_type, new_from_vertex, edge_ref);
         to_vertex->in_edges.emplace_back(edge_type, new_from_vertex, edge_ref);
 
+        auto *in_memory = static_cast<InMemoryStorage *>(storage_);
+        auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(in_memory->indices_.edge_type_index_.get());
+        mem_edge_type_index->UpdateOnEdgeModification(old_from_vertex, to_vertex, new_from_vertex, to_vertex, edge_ref,
+                                                      edge_type, transaction_);
+
         transaction_.manyDeltasCache.Invalidate(new_from_vertex, edge_type, EdgeDirection::OUT);
         transaction_.manyDeltasCache.Invalidate(old_from_vertex, edge_type, EdgeDirection::OUT);
         transaction_.manyDeltasCache.Invalidate(to_vertex, edge_type, EdgeDirection::IN);
@@ -659,6 +668,11 @@ Result<EdgeAccessor> InMemoryStorage::InMemoryAccessor::EdgeSetTo(EdgeAccessor *
         CreateAndLinkDelta(&transaction_, new_to_vertex, Delta::RemoveInEdgeTag(), edge_type, from_vertex, edge_ref);
         new_to_vertex->in_edges.emplace_back(edge_type, from_vertex, edge_ref);
 
+        auto *in_memory = static_cast<InMemoryStorage *>(storage_);
+        auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(in_memory->indices_.edge_type_index_.get());
+        mem_edge_type_index->UpdateOnEdgeModification(from_vertex, old_to_vertex, from_vertex, new_to_vertex, edge_ref,
+                                                      edge_type, transaction_);
+
         transaction_.manyDeltasCache.Invalidate(from_vertex, edge_type, EdgeDirection::OUT);
         transaction_.manyDeltasCache.Invalidate(old_to_vertex, edge_type, EdgeDirection::IN);
         transaction_.manyDeltasCache.Invalidate(new_to_vertex, edge_type, EdgeDirection::IN);
@@ -1264,6 +1278,18 @@ utils::BasicResult<StorageIndexDefinitionError, void> InMemoryStorage::InMemoryA
   return {};
 }
 
+utils::BasicResult<StorageIndexDefinitionError, void> InMemoryStorage::InMemoryAccessor::CreateIndex(
+    EdgeTypeId edge_type) {
+  MG_ASSERT(unique_guard_.owns_lock(), "Create index requires a unique access to the storage!");
+  auto *in_memory = static_cast<InMemoryStorage *>(storage_);
+  auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(in_memory->indices_.edge_type_index_.get());
+  if (!mem_edge_type_index->CreateIndex(edge_type, in_memory->vertices_.access())) {
+    return StorageIndexDefinitionError{IndexDefinitionError{}};
+  }
+  transaction_.md_deltas.emplace_back(MetadataDelta::edge_index_create, edge_type);
+  return {};
+}
+
 utils::BasicResult<StorageIndexDefinitionError, void> InMemoryStorage::InMemoryAccessor::DropIndex(LabelId label) {
   MG_ASSERT(unique_guard_.owns_lock(), "Dropping label index requires a unique access to the storage!");
   auto *in_memory = static_cast<InMemoryStorage *>(storage_);
@@ -1292,6 +1318,18 @@ utils::BasicResult<StorageIndexDefinitionError, void> InMemoryStorage::InMemoryA
   return {};
 }
 
+utils::BasicResult<StorageIndexDefinitionError, void> InMemoryStorage::InMemoryAccessor::DropIndex(
+    EdgeTypeId edge_type) {
+  MG_ASSERT(unique_guard_.owns_lock(), "Drop index requires a unique access to the storage!");
+  auto *in_memory = static_cast<InMemoryStorage *>(storage_);
+  auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(in_memory->indices_.edge_type_index_.get());
+  if (!mem_edge_type_index->DropIndex(edge_type)) {
+    return StorageIndexDefinitionError{IndexDefinitionError{}};
+  }
+  transaction_.md_deltas.emplace_back(MetadataDelta::edge_index_drop, edge_type);
+  return {};
+}
+
 utils::BasicResult<StorageExistenceConstraintDefinitionError, void>
 InMemoryStorage::InMemoryAccessor::CreateExistenceConstraint(LabelId label, PropertyId property) {
   MG_ASSERT(unique_guard_.owns_lock(), "Creating existence requires a unique access to the storage!");
@@ -1383,6 +1421,11 @@ VerticesIterable InMemoryStorage::InMemoryAccessor::Vertices(
       mem_label_property_index->Vertices(label, property, lower_bound, upper_bound, view, storage_, &transaction_));
 }
 
+EdgesIterable InMemoryStorage::InMemoryAccessor::Edges(EdgeTypeId edge_type, View view) {
+  auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(storage_->indices_.edge_type_index_.get());
+  return EdgesIterable(mem_edge_type_index->Edges(edge_type, view, storage_, &transaction_));
+}
+
 Transaction InMemoryStorage::CreateTransaction(
     IsolationLevel isolation_level, StorageMode storage_mode,
     memgraph::replication_coordination_glue::ReplicationRole replication_role) {
@@ -2017,6 +2060,10 @@ bool InMemoryStorage::AppendToWal(const Transaction &transaction, uint64_t final
         AppendToWalDataDefinition(durability::StorageMetadataOperation::LABEL_INDEX_CREATE, md_delta.label,
                                   final_commit_timestamp);
       } break;
+      case MetadataDelta::Action::EDGE_INDEX_CREATE: {
+        AppendToWalDataDefinition(durability::StorageMetadataOperation::EDGE_TYPE_INDEX_CREATE, md_delta.edge_type,
+                                  final_commit_timestamp);
+      } break;
       case MetadataDelta::Action::LABEL_PROPERTY_INDEX_CREATE: {
         const auto &info = md_delta.label_property;
         AppendToWalDataDefinition(durability::StorageMetadataOperation::LABEL_PROPERTY_INDEX_CREATE, info.label,
@@ -2026,6 +2073,10 @@ bool InMemoryStorage::AppendToWal(const Transaction &transaction, uint64_t final
         AppendToWalDataDefinition(durability::StorageMetadataOperation::LABEL_INDEX_DROP, md_delta.label,
                                   final_commit_timestamp);
       } break;
+      case MetadataDelta::Action::EDGE_INDEX_DROP: {
+        AppendToWalDataDefinition(durability::StorageMetadataOperation::EDGE_TYPE_INDEX_DROP, md_delta.edge_type,
+                                  final_commit_timestamp);
+      } break;
       case MetadataDelta::Action::LABEL_PROPERTY_INDEX_DROP: {
         const auto &info = md_delta.label_property;
         AppendToWalDataDefinition(durability::StorageMetadataOperation::LABEL_PROPERTY_INDEX_DROP, info.label,
@@ -2091,6 +2142,12 @@ void InMemoryStorage::AppendToWalDataDefinition(durability::StorageMetadataOpera
   repl_storage_state_.AppendOperation(operation, label, properties, stats, property_stats, final_commit_timestamp);
 }
 
+void InMemoryStorage::AppendToWalDataDefinition(durability::StorageMetadataOperation operation, EdgeTypeId edge_type,
+                                                uint64_t final_commit_timestamp) {
+  wal_file_->AppendOperation(operation, edge_type, final_commit_timestamp);
+  repl_storage_state_.AppendOperation(operation, edge_type, final_commit_timestamp);
+}
+
 void InMemoryStorage::AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label,
                                                 const std::set<PropertyId> &properties,
                                                 LabelPropertyIndexStats property_stats,
@@ -2240,7 +2297,8 @@ IndicesInfo InMemoryStorage::InMemoryAccessor::ListAllIndices() const {
   auto *mem_label_index = static_cast<InMemoryLabelIndex *>(in_memory->indices_.label_index_.get());
   auto *mem_label_property_index =
       static_cast<InMemoryLabelPropertyIndex *>(in_memory->indices_.label_property_index_.get());
-  return {mem_label_index->ListIndices(), mem_label_property_index->ListIndices()};
+  auto *mem_edge_type_index = static_cast<InMemoryEdgeTypeIndex *>(in_memory->indices_.edge_type_index_.get());
+  return {mem_label_index->ListIndices(), mem_label_property_index->ListIndices(), mem_edge_type_index->ListIndices()};
 }
 ConstraintsInfo InMemoryStorage::InMemoryAccessor::ListAllConstraints() const {
   const auto *mem_storage = static_cast<InMemoryStorage *>(storage_);

src/storage/v2/inmemory/storage.hpp

@@ -16,6 +16,7 @@
 #include <memory>
 #include <utility>
 #include "storage/v2/indices/label_index_stats.hpp"
+#include "storage/v2/inmemory/edge_type_index.hpp"
 #include "storage/v2/inmemory/label_index.hpp"
 #include "storage/v2/inmemory/label_property_index.hpp"
 #include "storage/v2/inmemory/replication/recovery.hpp"
@@ -53,6 +54,7 @@ class InMemoryStorage final : public Storage {
                                                     const InMemoryStorage *storage);
   friend class InMemoryLabelIndex;
   friend class InMemoryLabelPropertyIndex;
+  friend class InMemoryEdgeTypeIndex;
 
  public:
   enum class CreateSnapshotError : uint8_t { DisabledForReplica, ReachedMaxNumTries };
@@ -107,6 +109,8 @@ class InMemoryStorage final : public Storage {
                               const std::optional<utils::Bound<PropertyValue>> &lower_bound,
                               const std::optional<utils::Bound<PropertyValue>> &upper_bound, View view) override;
 
+    EdgesIterable Edges(EdgeTypeId edge_type, View view) override;
+
     /// Return approximate number of all vertices in the database.
     /// Note that this is always an over-estimate and never an under-estimate.
     uint64_t ApproximateVertexCount() const override {
@@ -145,6 +149,10 @@ class InMemoryStorage final : public Storage {
           label, property, lower, upper);
     }
 
+    uint64_t ApproximateEdgeCount(EdgeTypeId id) const override {
+      return static_cast<InMemoryStorage *>(storage_)->indices_.edge_type_index_->ApproximateEdgeCount(id);
+    }
+
     template <typename TResult, typename TIndex, typename TIndexKey>
     std::optional<TResult> GetIndexStatsForIndex(TIndex *index, TIndexKey &&key) const {
       return index->GetIndexStats(key);
@@ -204,6 +212,10 @@ class InMemoryStorage final : public Storage {
       return static_cast<InMemoryStorage *>(storage_)->indices_.label_property_index_->IndexExists(label, property);
     }
 
+    bool EdgeTypeIndexExists(EdgeTypeId edge_type) const override {
+      return static_cast<InMemoryStorage *>(storage_)->indices_.edge_type_index_->IndexExists(edge_type);
+    }
+
     IndicesInfo ListAllIndices() const override;
 
     ConstraintsInfo ListAllConstraints() const override;
@@ -239,6 +251,14 @@ class InMemoryStorage final : public Storage {
     /// @throw std::bad_alloc
     utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(LabelId label, PropertyId property) override;
 
+    /// Create an index.
+    /// Returns void if the index has been created.
+    /// Returns `StorageIndexDefinitionError` if an error occures. Error can be:
+    /// * `ReplicationError`:  there is at least one SYNC replica that has not confirmed receiving the transaction.
+    /// * `IndexDefinitionError`: the index already exists.
+    /// @throw std::bad_alloc
+    utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(EdgeTypeId edge_type) override;
+
     /// Drop an existing index.
     /// Returns void if the index has been dropped.
     /// Returns `StorageIndexDefinitionError` if an error occures. Error can be:
@@ -253,6 +273,13 @@ class InMemoryStorage final : public Storage {
     /// * `IndexDefinitionError`: the index does not exist.
     utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(LabelId label, PropertyId property) override;
 
+    /// Drop an existing index.
+    /// Returns void if the index has been dropped.
+    /// Returns `StorageIndexDefinitionError` if an error occures. Error can be:
+    /// * `ReplicationError`:  there is at least one SYNC replica that has not confirmed receiving the transaction.
+    /// * `IndexDefinitionError`: the index does not exist.
+    utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(EdgeTypeId edge_type) override;
+
     /// Returns void if the existence constraint has been created.
     /// Returns `StorageExistenceConstraintDefinitionError` if an error occures. Error can be:
     /// * `ReplicationError`: there is at least one SYNC replica that has not confirmed receiving the transaction.
@@ -374,20 +401,17 @@ class InMemoryStorage final : public Storage {
   /// Return true in all cases excepted if any sync replicas have not sent confirmation.
   [[nodiscard]] bool AppendToWal(const Transaction &transaction, uint64_t final_commit_timestamp,
                                  DatabaseAccessProtector db_acc);
-  /// Return true in all cases excepted if any sync replicas have not sent confirmation.
   void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label,
                                  uint64_t final_commit_timestamp);
-  /// Return true in all cases excepted if any sync replicas have not sent confirmation.
+  void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, EdgeTypeId edge_type,
+                                 uint64_t final_commit_timestamp);
   void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label,
                                  const std::set<PropertyId> &properties, uint64_t final_commit_timestamp);
-  /// Return true in all cases excepted if any sync replicas have not sent confirmation.
   void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label, LabelIndexStats stats,
                                  uint64_t final_commit_timestamp);
-  /// Return true in all cases excepted if any sync replicas have not sent confirmation.
   void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label,
                                  const std::set<PropertyId> &properties, LabelPropertyIndexStats property_stats,
                                  uint64_t final_commit_timestamp);
-  /// Return true in all cases excepted if any sync replicas have not sent confirmation.
   void AppendToWalDataDefinition(durability::StorageMetadataOperation operation, LabelId label,
                                  const std::set<PropertyId> &properties, LabelIndexStats stats,
                                  LabelPropertyIndexStats property_stats, uint64_t final_commit_timestamp);

src/storage/v2/metadata_delta.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -35,6 +35,8 @@ struct MetadataDelta {
     LABEL_PROPERTY_INDEX_DROP,
     LABEL_PROPERTY_INDEX_STATS_SET,
     LABEL_PROPERTY_INDEX_STATS_CLEAR,
+    EDGE_INDEX_CREATE,
+    EDGE_INDEX_DROP,
     EXISTENCE_CONSTRAINT_CREATE,
     EXISTENCE_CONSTRAINT_DROP,
     UNIQUE_CONSTRAINT_CREATE,
@@ -57,6 +59,10 @@ struct MetadataDelta {
   } label_property_index_stats_set;
   static constexpr struct LabelPropertyIndexStatsClear {
   } label_property_index_stats_clear;
+  static constexpr struct EdgeIndexCreate {
+  } edge_index_create;
+  static constexpr struct EdgeIndexDrop {
+  } edge_index_drop;
   static constexpr struct ExistenceConstraintCreate {
   } existence_constraint_create;
   static constexpr struct ExistenceConstraintDrop {
@@ -87,6 +93,11 @@ struct MetadataDelta {
   MetadataDelta(LabelPropertyIndexStatsClear /*tag*/, LabelId label)
       : action(Action::LABEL_PROPERTY_INDEX_STATS_CLEAR), label{label} {}
 
+  MetadataDelta(EdgeIndexCreate /*tag*/, EdgeTypeId edge_type)
+      : action(Action::EDGE_INDEX_CREATE), edge_type(edge_type) {}
+
+  MetadataDelta(EdgeIndexDrop /*tag*/, EdgeTypeId edge_type) : action(Action::EDGE_INDEX_DROP), edge_type(edge_type) {}
+
   MetadataDelta(ExistenceConstraintCreate /*tag*/, LabelId label, PropertyId property)
       : action(Action::EXISTENCE_CONSTRAINT_CREATE), label_property{label, property} {}
 
@@ -114,6 +125,8 @@ struct MetadataDelta {
       case Action::LABEL_PROPERTY_INDEX_DROP:
       case Action::LABEL_PROPERTY_INDEX_STATS_SET:
       case Action::LABEL_PROPERTY_INDEX_STATS_CLEAR:
+      case Action::EDGE_INDEX_CREATE:
+      case Action::EDGE_INDEX_DROP:
       case Action::EXISTENCE_CONSTRAINT_CREATE:
       case Action::EXISTENCE_CONSTRAINT_DROP:
         break;
@@ -129,6 +142,8 @@ struct MetadataDelta {
   union {
     LabelId label;
 
+    EdgeTypeId edge_type;
+
     struct {
       LabelId label;
       PropertyId property;

src/storage/v2/replication/replication_client.cpp

@@ -76,13 +76,37 @@ void ReplicationStorageClient::UpdateReplicaState(Storage *storage, DatabaseAcce
     }
   }
   if (branching_point) {
-    spdlog::error(
+    auto replica_state = replica_state_.Lock();
-        "You cannot register Replica {} to this Main because at one point "
+    if (*replica_state == replication::ReplicaState::DIVERGED_FROM_MAIN) {
-        "Replica {} acted as the Main instance. Both the Main and Replica {} "
+      return;
-        "now hold unique data. Please resolve data conflicts and start the "
+    }
-        "replication on a clean instance.",
+    *replica_state = replication::ReplicaState::DIVERGED_FROM_MAIN;
-        client_.name_, client_.name_, client_.name_);
+
-    replica_state_.WithLock([](auto &val) { val = replication::ReplicaState::DIVERGED_FROM_MAIN; });
+    auto log_error = [client_name = client_.name_]() {
+      spdlog::error(
+          "You cannot register Replica {} to this Main because at one point "
+          "Replica {} acted as the Main instance. Both the Main and Replica {} "
+          "now hold unique data. Please resolve data conflicts and start the "
+          "replication on a clean instance.",
+          client_name, client_name, client_name);
+    };
+#ifdef MG_ENTERPRISE
+    if (!FLAGS_coordinator_server_port) {
+      log_error();
+      return;
+    }
+    client_.thread_pool_.AddTask([storage, gk = std::move(db_acc), this] {
+      const auto [success, timestamp] = this->ForceResetStorage(storage);
+      if (success) {
+        spdlog::info("Successfully reset storage of REPLICA {} to timestamp {}.", client_.name_, timestamp);
+        return;
+      }
+      spdlog::error("You cannot register REPLICA {} to this MAIN because MAIN couldn't reset REPLICA's storage.",
+                    client_.name_);
+    });
+#else
+    log_error();
+#endif
     return;
   }
 
@@ -265,8 +289,6 @@ void ReplicationStorageClient::RecoverReplica(uint64_t replica_commit, memgraph:
   spdlog::debug("Starting replica recovery");
   auto *mem_storage = static_cast<InMemoryStorage *>(storage);
 
-  // TODO(antoniofilipovic): Can we get stuck here in while loop if replica commit timestamp is not updated when using
-  // only snapshot
   while (true) {
     auto file_locker = mem_storage->file_retainer_.AddLocker();
 
@@ -335,6 +357,21 @@ void ReplicationStorageClient::RecoverReplica(uint64_t replica_commit, memgraph:
   }
 }
 
+std::pair<bool, uint64_t> ReplicationStorageClient::ForceResetStorage(memgraph::storage::Storage *storage) {
+  utils::OnScopeExit set_to_maybe_behind{
+      [this]() { replica_state_.WithLock([](auto &state) { state = replication::ReplicaState::MAYBE_BEHIND; }); }};
+  try {
+    auto stream{client_.rpc_client_.Stream<replication::ForceResetStorageRpc>(main_uuid_, storage->uuid())};
+    const auto res = stream.AwaitResponse();
+    return std::pair{res.success, res.current_commit_timestamp};
+  } catch (const rpc::RpcFailedException &) {
+    spdlog::error(
+        utils::MessageWithLink("Couldn't ForceReset data to {}.", client_.name_, "https://memgr.ph/replication"));
+  }
+
+  return {false, 0};
+}
+
 ////// ReplicaStream //////
 ReplicaStream::ReplicaStream(Storage *storage, rpc::Client &rpc_client, const uint64_t current_seq_num,
                              utils::UUID main_uuid)
@@ -370,6 +407,12 @@ void ReplicaStream::AppendOperation(durability::StorageMetadataOperation operati
                   timestamp);
 }
 
+void ReplicaStream::AppendOperation(durability::StorageMetadataOperation operation, EdgeTypeId edge_type,
+                                    uint64_t timestamp) {
+  replication::Encoder encoder(stream_.GetBuilder());
+  EncodeOperation(&encoder, storage_->name_id_mapper_.get(), operation, edge_type, timestamp);
+}
+
 replication::AppendDeltasRes ReplicaStream::Finalize() { return stream_.AwaitResponse(); }
 
 }  // namespace memgraph::storage

src/storage/v2/replication/replication_client.hpp

@@ -65,6 +65,9 @@ class ReplicaStream {
                        const std::set<PropertyId> &properties, const LabelIndexStats &stats,
                        const LabelPropertyIndexStats &property_stats, uint64_t timestamp);
 
+  /// @throw rpc::RpcFailedException
+  void AppendOperation(durability::StorageMetadataOperation operation, EdgeTypeId edge_type, uint64_t timestamp);
+
   /// @throw rpc::RpcFailedException
   replication::AppendDeltasRes Finalize();
 
@@ -188,6 +191,13 @@ class ReplicationStorageClient {
    */
   void UpdateReplicaState(Storage *storage, DatabaseAccessProtector db_acc);
 
+  /**
+   * @brief Forcefully reset storage to as it is when started from scratch.
+   *
+   * @param storage pointer to the storage associated with the client
+   */
+  std::pair<bool, uint64_t> ForceResetStorage(Storage *storage);
+
   void LogRpcFailure();
 
   /**

src/storage/v2/replication/replication_storage_state.cpp

@@ -53,6 +53,16 @@ void ReplicationStorageState::AppendOperation(durability::StorageMetadataOperati
   });
 }
 
+void ReplicationStorageState::AppendOperation(durability::StorageMetadataOperation operation, EdgeTypeId edge_type,
+                                              uint64_t final_commit_timestamp) {
+  replication_clients_.WithLock([&](auto &clients) {
+    for (auto &client : clients) {
+      client->IfStreamingTransaction(
+          [&](auto &stream) { stream.AppendOperation(operation, edge_type, final_commit_timestamp); });
+    }
+  });
+}
+
 bool ReplicationStorageState::FinalizeTransaction(uint64_t timestamp, Storage *storage,
                                                   DatabaseAccessProtector db_acc) {
   return replication_clients_.WithLock([=, db_acc = std::move(db_acc)](auto &clients) mutable {

src/storage/v2/replication/replication_storage_state.hpp

@@ -46,6 +46,8 @@ struct ReplicationStorageState {
   void AppendOperation(durability::StorageMetadataOperation operation, LabelId label,
                        const std::set<PropertyId> &properties, const LabelIndexStats &stats,
                        const LabelPropertyIndexStats &property_stats, uint64_t final_commit_timestamp);
+  void AppendOperation(durability::StorageMetadataOperation operation, EdgeTypeId edge_type,
+                       uint64_t final_commit_timestamp);
   bool FinalizeTransaction(uint64_t timestamp, Storage *storage, DatabaseAccessProtector db_acc);
 
   // Getters

src/storage/v2/replication/rpc.cpp

@@ -59,6 +59,19 @@ void TimestampRes::Save(const TimestampRes &self, memgraph::slk::Builder *builde
   memgraph::slk::Save(self, builder);
 }
 void TimestampRes::Load(TimestampRes *self, memgraph::slk::Reader *reader) { memgraph::slk::Load(self, reader); }
+
+void ForceResetStorageReq::Save(const ForceResetStorageReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void ForceResetStorageReq::Load(ForceResetStorageReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
+void ForceResetStorageRes::Save(const ForceResetStorageRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self, builder);
+}
+void ForceResetStorageRes::Load(ForceResetStorageRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(self, reader);
+}
 }  // namespace storage::replication
 
 constexpr utils::TypeInfo storage::replication::AppendDeltasReq::kType{utils::TypeId::REP_APPEND_DELTAS_REQ,
@@ -97,6 +110,12 @@ constexpr utils::TypeInfo storage::replication::TimestampReq::kType{utils::TypeI
 constexpr utils::TypeInfo storage::replication::TimestampRes::kType{utils::TypeId::REP_TIMESTAMP_RES, "TimestampRes",
                                                                     nullptr};
 
+constexpr utils::TypeInfo storage::replication::ForceResetStorageReq::kType{utils::TypeId::REP_FORCE_RESET_STORAGE_REQ,
+                                                                            "ForceResetStorageReq", nullptr};
+
+constexpr utils::TypeInfo storage::replication::ForceResetStorageRes::kType{utils::TypeId::REP_FORCE_RESET_STORAGE_RES,
+                                                                            "ForceResetStorageRes", nullptr};
+
 // Autogenerated SLK serialization code
 namespace slk {
 // Serialize code for TimestampRes
@@ -255,6 +274,30 @@ void Load(memgraph::storage::replication::AppendDeltasReq *self, memgraph::slk::
   memgraph::slk::Load(&self->seq_num, reader);
 }
 
+// Serialize code for ForceResetStorageReq
+
+void Save(const memgraph::storage::replication::ForceResetStorageReq &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.main_uuid, builder);
+  memgraph::slk::Save(self.db_uuid, builder);
+}
+
+void Load(memgraph::storage::replication::ForceResetStorageReq *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->main_uuid, reader);
+  memgraph::slk::Load(&self->db_uuid, reader);
+}
+
+// Serialize code for ForceResetStorageRes
+
+void Save(const memgraph::storage::replication::ForceResetStorageRes &self, memgraph::slk::Builder *builder) {
+  memgraph::slk::Save(self.success, builder);
+  memgraph::slk::Save(self.current_commit_timestamp, builder);
+}
+
+void Load(memgraph::storage::replication::ForceResetStorageRes *self, memgraph::slk::Reader *reader) {
+  memgraph::slk::Load(&self->success, reader);
+  memgraph::slk::Load(&self->current_commit_timestamp, reader);
+}
+
 // Serialize SalientConfig
 
 void Save(const memgraph::storage::SalientConfig &self, memgraph::slk::Builder *builder) {

src/storage/v2/replication/rpc.hpp

@@ -210,6 +210,36 @@ struct TimestampRes {
 
 using TimestampRpc = rpc::RequestResponse<TimestampReq, TimestampRes>;
 
+struct ForceResetStorageReq {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(ForceResetStorageReq *self, memgraph::slk::Reader *reader);
+  static void Save(const ForceResetStorageReq &self, memgraph::slk::Builder *builder);
+  ForceResetStorageReq() = default;
+  explicit ForceResetStorageReq(const utils::UUID &main_uuid, const utils::UUID &db_uuid)
+      : main_uuid{main_uuid}, db_uuid{db_uuid} {}
+
+  utils::UUID main_uuid;
+  utils::UUID db_uuid;
+};
+
+struct ForceResetStorageRes {
+  static const utils::TypeInfo kType;
+  static const utils::TypeInfo &GetTypeInfo() { return kType; }
+
+  static void Load(ForceResetStorageRes *self, memgraph::slk::Reader *reader);
+  static void Save(const ForceResetStorageRes &self, memgraph::slk::Builder *builder);
+  ForceResetStorageRes() = default;
+  ForceResetStorageRes(bool success, uint64_t current_commit_timestamp)
+      : success(success), current_commit_timestamp(current_commit_timestamp) {}
+
+  bool success;
+  uint64_t current_commit_timestamp;
+};
+
+using ForceResetStorageRpc = rpc::RequestResponse<ForceResetStorageReq, ForceResetStorageRes>;
+
 }  // namespace memgraph::storage::replication
 
 // SLK serialization declarations
@@ -267,4 +297,12 @@ void Save(const memgraph::storage::SalientConfig &self, memgraph::slk::Builder *
 
 void Load(memgraph::storage::SalientConfig *self, memgraph::slk::Reader *reader);
 
+void Save(const memgraph::storage::replication::ForceResetStorageReq &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::ForceResetStorageReq *self, memgraph::slk::Reader *reader);
+
+void Save(const memgraph::storage::replication::ForceResetStorageRes &self, memgraph::slk::Builder *builder);
+
+void Load(memgraph::storage::replication::ForceResetStorageRes *self, memgraph::slk::Reader *reader);
+
 }  // namespace memgraph::slk

src/storage/v2/storage.hpp

@@ -30,6 +30,7 @@
 #include "storage/v2/durability/paths.hpp"
 #include "storage/v2/durability/wal.hpp"
 #include "storage/v2/edge_accessor.hpp"
+#include "storage/v2/edges_iterable.hpp"
 #include "storage/v2/indices/indices.hpp"
 #include "storage/v2/mvcc.hpp"
 #include "storage/v2/replication/enums.hpp"
@@ -61,6 +62,7 @@ class EdgeAccessor;
 struct IndicesInfo {
   std::vector<LabelId> label;
   std::vector<std::pair<LabelId, PropertyId>> label_property;
+  std::vector<EdgeTypeId> edge_type;
 };
 
 struct ConstraintsInfo {
@@ -172,6 +174,8 @@ class Storage {
                                       const std::optional<utils::Bound<PropertyValue>> &lower_bound,
                                       const std::optional<utils::Bound<PropertyValue>> &upper_bound, View view) = 0;
 
+    virtual EdgesIterable Edges(EdgeTypeId edge_type, View view) = 0;
+
     virtual Result<std::optional<VertexAccessor>> DeleteVertex(VertexAccessor *vertex);
 
     virtual Result<std::optional<std::pair<VertexAccessor, std::vector<EdgeAccessor>>>> DetachDeleteVertex(
@@ -192,6 +196,8 @@ class Storage {
                                             const std::optional<utils::Bound<PropertyValue>> &lower,
                                             const std::optional<utils::Bound<PropertyValue>> &upper) const = 0;
 
+    virtual uint64_t ApproximateEdgeCount(EdgeTypeId id) const = 0;
+
     virtual std::optional<storage::LabelIndexStats> GetIndexStats(const storage::LabelId &label) const = 0;
 
     virtual std::optional<storage::LabelPropertyIndexStats> GetIndexStats(
@@ -224,6 +230,8 @@ class Storage {
 
     virtual bool LabelPropertyIndexExists(LabelId label, PropertyId property) const = 0;
 
+    virtual bool EdgeTypeIndexExists(EdgeTypeId edge_type) const = 0;
+
     virtual IndicesInfo ListAllIndices() const = 0;
 
     virtual ConstraintsInfo ListAllConstraints() const = 0;
@@ -268,10 +276,14 @@ class Storage {
 
     virtual utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(LabelId label, PropertyId property) = 0;
 
+    virtual utils::BasicResult<StorageIndexDefinitionError, void> CreateIndex(EdgeTypeId edge_type) = 0;
+
     virtual utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(LabelId label) = 0;
 
     virtual utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(LabelId label, PropertyId property) = 0;
 
+    virtual utils::BasicResult<StorageIndexDefinitionError, void> DropIndex(EdgeTypeId edge_type) = 0;
+
     virtual utils::BasicResult<StorageExistenceConstraintDefinitionError, void> CreateExistenceConstraint(
         LabelId label, PropertyId property) = 0;
 

src/storage/v2/vertices_iterable.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source
@@ -10,7 +10,6 @@
 // licenses/APL.txt.
 
 #include "storage/v2/vertices_iterable.hpp"
-
 namespace memgraph::storage {
 
 VerticesIterable::VerticesIterable(AllVerticesIterable vertices) : type_(Type::ALL) {

src/storage/v2/vertices_iterable.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/utils/atomic_memory_block.hpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/utils/event_counter.cpp

@@ -26,6 +26,7 @@
   M(ScanAllByLabelPropertyValueOperator, Operator, "Number of times ScanAllByLabelPropertyValue operator was used.") \
   M(ScanAllByLabelPropertyOperator, Operator, "Number of times ScanAllByLabelProperty operator was used.")           \
   M(ScanAllByIdOperator, Operator, "Number of times ScanAllById operator was used.")                                 \
+  M(ScanAllByEdgeTypeOperator, Operator, "Number of times ScanAllByEdgeTypeOperator operator was used.")             \
   M(ExpandOperator, Operator, "Number of times Expand operator was used.")                                           \
   M(ExpandVariableOperator, Operator, "Number of times ExpandVariable operator was used.")                           \
   M(ConstructNamedPathOperator, Operator, "Number of times ConstructNamedPath operator was used.")                   \

src/utils/functional.hpp

@@ -19,9 +19,9 @@
 namespace memgraph::utils {
 
 template <template <typename, typename...> class Container, typename T, typename Allocator = std::allocator<T>,
-          typename F, typename R = std::invoke_result_t<F, T>>
+          typename F = std::identity, typename R = std::decay_t<std::invoke_result_t<F, T>>>
 requires ranges::range<Container<T, Allocator>> &&
-    (!std::same_as<Container<T, Allocator>, std::string>)auto fmap(F &&f, const Container<T, Allocator> &v)
+    (!std::same_as<Container<T, Allocator>, std::string>)auto fmap(const Container<T, Allocator> &v, F &&f = {})
         -> std::vector<R> {
   return v | ranges::views::transform(std::forward<F>(f)) | ranges::to<std::vector<R>>();
 }

src/utils/settings.cpp

@@ -1,4 +1,4 @@
-// Copyright 2023 Memgraph Ltd.
+// Copyright 2024 Memgraph Ltd.
 //
 // Use of this software is governed by the Business Source License
 // included in the file licenses/BSL.txt; by using this file, you agree to be bound by the terms of the Business Source

src/utils/typeinfo.hpp

@@ -32,6 +32,7 @@ enum class TypeId : uint64_t {
   SCAN_ALL_BY_LABEL_PROPERTY_VALUE,
   SCAN_ALL_BY_LABEL_PROPERTY,
   SCAN_ALL_BY_ID,
+  SCAN_ALL_BY_EDGE_TYPE,
   EXPAND_COMMON,
   EXPAND,
   EXPANSION_LAMBDA,
@@ -68,6 +69,7 @@ enum class TypeId : uint64_t {
   APPLY,
   INDEXED_JOIN,
   HASH_JOIN,
+  ROLLUP_APPLY,
 
   // Replication
   // NOTE: these NEED to be stable in the 2000+ range (see rpc version)
@@ -99,6 +101,8 @@ enum class TypeId : uint64_t {
   REP_DROP_AUTH_DATA_RES,
   REP_TRY_SET_MAIN_UUID_REQ,
   REP_TRY_SET_MAIN_UUID_RES,
+  REP_FORCE_RESET_STORAGE_REQ,
+  REP_FORCE_RESET_STORAGE_RES,
 
   // Coordinator
   COORD_FAILOVER_REQ,
@@ -182,6 +186,7 @@ enum class TypeId : uint64_t {
   AST_EXPLAIN_QUERY,
   AST_PROFILE_QUERY,
   AST_INDEX_QUERY,
+  AST_EDGE_INDEX_QUERY,
   AST_CREATE,
   AST_CALL_PROCEDURE,
   AST_MATCH,