Use custom allocator in Evaluator through context

Summary:
Micro benchmarks show improvements in performance of MapLiteral from 5%
to 40% depending on the size of the input. On the other hand, a sequence
of AdditionOperators behaves the same with both allocation schemes.

Reviewers: mtomic, mferencevic, msantl

Reviewed By: mtomic

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D2132

src/distributed/produce_rpc_server.cpp

@@ -22,6 +22,8 @@ ProduceRpcServer::OngoingProduce::OngoingProduce(
           query::kExecutionMemoryBlockSize)),
       cursor_(plan_pack.plan->MakeCursor(dba_.get(), execution_memory_.get())) {
   context_.symbol_table = plan_pack.symbol_table;
+  // TODO: Maybe we want a seperate MemoryResource per pull evaluation
+  context_.evaluation_context.memory = execution_memory_.get();
   context_.evaluation_context.timestamp = timestamp;
   context_.evaluation_context.parameters = parameters;
   context_.evaluation_context.properties =

src/query/context.hpp

@@ -10,6 +10,12 @@ namespace query {
 static constexpr size_t kExecutionMemoryBlockSize = 1U * 1024U * 1024U;
 
 struct EvaluationContext {
+  /// Memory for allocations during evaluation of a *single* Pull call.
+  ///
+  /// Although the assigned memory may live longer than the duration of a Pull
+  /// (e.g. memory is the same as the whole execution memory), you have to treat
+  /// it as if the lifetime is only valid during the Pull.
+  utils::MemoryResource *memory{utils::NewDeleteResource()};
   int64_t timestamp{-1};
   Parameters parameters;
   /// All properties indexable via PropertyIx

src/query/interpret/eval.hpp

@@ -32,6 +32,8 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
 
   using ExpressionVisitor<TypedValue>::Visit;
 
+  utils::MemoryResource *GetMemoryResource() const { return ctx_->memory; }
+
   TypedValue Visit(NamedExpression &named_expression) override {
     const auto &symbol = symbol_table_->at(named_expression);
     auto value = named_expression.expression_->Accept(*this);
@@ -40,7 +42,7 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
   }
 
   TypedValue Visit(Identifier &ident) override {
-    auto value = frame_->at(symbol_table_->at(ident));
+    TypedValue value(frame_->at(symbol_table_->at(ident)), ctx_->memory);
     SwitchAccessors(value);
     return value;
   }
@@ -124,21 +126,21 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     auto literal = in_list.expression1_->Accept(*this);
     auto _list = in_list.expression2_->Accept(*this);
     if (_list.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     // Exceptions have higher priority than returning nulls when list expression
     // is not null.
     if (_list.type() != TypedValue::Type::List) {
       throw QueryRuntimeException("IN expected a list, got {}.", _list.type());
     }
-    auto list = _list.ValueList();
+    const auto &list = _list.ValueList();
 
     // If literal is NULL there is no need to try to compare it with every
     // element in the list since result of every comparison will be NULL. There
     // is one special case that we must test explicitly: if list is empty then
     // result is false since no comparison will be performed.
-    if (list.empty()) return TypedValue(false);
-    if (literal.IsNull()) return TypedValue();
+    if (list.empty()) return TypedValue(false, ctx_->memory);
+    if (literal.IsNull()) return TypedValue(ctx_->memory);
 
     auto has_null = false;
     for (const auto &element : list) {
@@ -146,13 +148,13 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
       if (result.IsNull()) {
         has_null = true;
       } else if (result.Value<bool>()) {
-        return TypedValue(true);
+        return TypedValue(true, ctx_->memory);
       }
     }
     if (has_null) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
-    return TypedValue(false);
+    return TypedValue(false, ctx_->memory);
   }
 
   TypedValue Visit(SubscriptOperator &list_indexing) override {
@@ -164,29 +166,37 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
           "Expected a list, a map, a node or an edge to index with '[]', got "
           "{}.",
           lhs.type());
-    if (lhs.IsNull() || index.IsNull()) return TypedValue();
+    if (lhs.IsNull() || index.IsNull()) return TypedValue(ctx_->memory);
     if (lhs.IsList()) {
       if (!index.IsInt())
         throw QueryRuntimeException(
             "Expected an integer as a list index, got {}.", index.type());
       auto index_int = index.Value<int64_t>();
-      const auto &list = lhs.ValueList();
+      // NOTE: Take non-const reference to list, so that we can move out the
+      // indexed element as the result.
+      auto &list = lhs.ValueList();
       if (index_int < 0) {
         index_int += static_cast<int64_t>(list.size());
       }
       if (index_int >= static_cast<int64_t>(list.size()) || index_int < 0)
-        return TypedValue();
-      return list[index_int];
+        return TypedValue(ctx_->memory);
+      // NOTE: Explicit move is needed, so that we return the move constructed
+      // value and preserve the correct MemoryResource.
+      return std::move(list[index_int]);
     }
 
     if (lhs.IsMap()) {
       if (!index.IsString())
         throw QueryRuntimeException("Expected a string as a map index, got {}.",
                                     index.type());
-      const auto &map = lhs.ValueMap();
+      // NOTE: Take non-const reference to map, so that we can move out the
+      // looked-up element as the result.
+      auto &map = lhs.ValueMap();
       auto found = map.find(index.ValueString());
-      if (found == map.end()) return TypedValue();
-      return found->second;
+      if (found == map.end()) return TypedValue(ctx_->memory);
+      // NOTE: Explicit move is needed, so that we return the move constructed
+      // value and preserve the correct MemoryResource.
+      return std::move(found->second);
     }
 
     if (lhs.IsVertex()) {
@@ -194,7 +204,8 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
         throw QueryRuntimeException(
             "Expected a string as a property name, got {}.", index.type());
       return TypedValue(lhs.Value<VertexAccessor>().PropsAt(
-          dba_->Property(std::string(index.ValueString()))));
+                            dba_->Property(std::string(index.ValueString()))),
+                        ctx_->memory);
     }
 
     if (lhs.IsEdge()) {
@@ -202,11 +213,12 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
         throw QueryRuntimeException(
             "Expected a string as a property name, got {}.", index.type());
       return TypedValue(lhs.Value<EdgeAccessor>().PropsAt(
-          dba_->Property(std::string(index.ValueString()))));
+                            dba_->Property(std::string(index.ValueString()))),
+                        ctx_->memory);
     }
 
     // lhs is Null
-    return TypedValue();
+    return TypedValue(ctx_->memory);
   }
 
   TypedValue Visit(ListSlicingOperator &op) override {
@@ -225,7 +237,7 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
         }
         return bound;
       }
-      return TypedValue(default_value);
+      return TypedValue(default_value, ctx_->memory);
     };
     auto _upper_bound =
         get_bound(op.upper_bound_, std::numeric_limits<int64_t>::max());
@@ -240,7 +252,7 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     }
 
     if (is_null) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     const auto &list = _list.ValueList();
     auto normalise_bound = [&](int64_t bound) {
@@ -253,33 +265,39 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     auto lower_bound = normalise_bound(_lower_bound.Value<int64_t>());
     auto upper_bound = normalise_bound(_upper_bound.Value<int64_t>());
     if (upper_bound <= lower_bound) {
-      return TypedValue(std::vector<TypedValue>());
+      return TypedValue(TypedValue::TVector(ctx_->memory), ctx_->memory);
     }
-    return TypedValue(std::vector<TypedValue>(list.begin() + lower_bound,
-                                              list.begin() + upper_bound));
+    return TypedValue(TypedValue::TVector(
+        list.begin() + lower_bound, list.begin() + upper_bound, ctx_->memory));
   }
 
   TypedValue Visit(IsNullOperator &is_null) override {
     auto value = is_null.expression_->Accept(*this);
-    return TypedValue(value.IsNull());
+    return TypedValue(value.IsNull(), ctx_->memory);
   }
 
   TypedValue Visit(PropertyLookup &property_lookup) override {
     auto expression_result = property_lookup.expression_->Accept(*this);
     switch (expression_result.type()) {
       case TypedValue::Type::Null:
-        return TypedValue();
+        return TypedValue(ctx_->memory);
       case TypedValue::Type::Vertex:
         return TypedValue(expression_result.Value<VertexAccessor>().PropsAt(
-            GetProperty(property_lookup.property_)));
+                              GetProperty(property_lookup.property_)),
+                          ctx_->memory);
       case TypedValue::Type::Edge:
         return TypedValue(expression_result.Value<EdgeAccessor>().PropsAt(
-            GetProperty(property_lookup.property_)));
+                              GetProperty(property_lookup.property_)),
+                          ctx_->memory);
       case TypedValue::Type::Map: {
-        const auto &map = expression_result.ValueMap();
+        // NOTE: Take non-const reference to map, so that we can move out the
+        // looked-up element as the result.
+        auto &map = expression_result.ValueMap();
         auto found = map.find(property_lookup.property_.name.c_str());
-        if (found == map.end()) return TypedValue();
-        return found->second;
+        if (found == map.end()) return TypedValue(ctx_->memory);
+        // NOTE: Explicit move is needed, so that we return the move constructed
+        // value and preserve the correct MemoryResource.
+        return std::move(found->second);
       }
       default:
         throw QueryRuntimeException(
@@ -291,15 +309,15 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     auto expression_result = labels_test.expression_->Accept(*this);
     switch (expression_result.type()) {
       case TypedValue::Type::Null:
-        return TypedValue();
+        return TypedValue(ctx_->memory);
       case TypedValue::Type::Vertex: {
-        auto vertex = expression_result.Value<VertexAccessor>();
-        for (const auto label : labels_test.labels_) {
+        const auto &vertex = expression_result.Value<VertexAccessor>();
+        for (const auto &label : labels_test.labels_) {
           if (!vertex.has_label(GetLabel(label))) {
-            return TypedValue(false);
+            return TypedValue(false, ctx_->memory);
           }
         }
-        return TypedValue(true);
+        return TypedValue(true, ctx_->memory);
       }
       default:
         throw QueryRuntimeException("Only nodes have labels.");
@@ -309,26 +327,26 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
   TypedValue Visit(PrimitiveLiteral &literal) override {
     // TODO: no need to evaluate constants, we can write it to frame in one
     // of the previous phases.
-    return TypedValue(literal.value_);
+    return TypedValue(literal.value_, ctx_->memory);
   }
 
   TypedValue Visit(ListLiteral &literal) override {
-    std::vector<TypedValue> result;
+    TypedValue::TVector result(ctx_->memory);
     result.reserve(literal.elements_.size());
     for (const auto &expression : literal.elements_)
       result.emplace_back(expression->Accept(*this));
-    return TypedValue(result);
+    return TypedValue(result, ctx_->memory);
   }
 
   TypedValue Visit(MapLiteral &literal) override {
-    std::map<std::string, TypedValue> result;
+    TypedValue::TMap result(ctx_->memory);
     for (const auto &pair : literal.elements_)
       result.emplace(pair.first.name, pair.second->Accept(*this));
-    return TypedValue(result);
+    return TypedValue(result, ctx_->memory);
   }
 
   TypedValue Visit(Aggregation &aggregation) override {
-    auto value = frame_->at(symbol_table_->at(aggregation));
+    TypedValue value(frame_->at(symbol_table_->at(aggregation)), ctx_->memory);
     // Aggregation is probably always simple type, but let's switch accessor
     // just to be sure.
     SwitchAccessors(value);
@@ -343,39 +361,46 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     }
 
     for (int64_t i = 0; i < exprs.size(); ++i) {
-      TypedValue val = exprs[i]->Accept(*this);
+      TypedValue val(exprs[i]->Accept(*this), ctx_->memory);
       if (!val.IsNull()) {
         return val;
       }
     }
 
-    return TypedValue();
+    return TypedValue(ctx_->memory);
   }
 
   TypedValue Visit(Function &function) override {
     // Stack allocate evaluated arguments when there's a small number of them.
     if (function.arguments_.size() <= 8) {
-      TypedValue arguments[8];
+      TypedValue arguments[8] = {
+          TypedValue(ctx_->memory), TypedValue(ctx_->memory),
+          TypedValue(ctx_->memory), TypedValue(ctx_->memory),
+          TypedValue(ctx_->memory), TypedValue(ctx_->memory),
+          TypedValue(ctx_->memory), TypedValue(ctx_->memory)};
       for (size_t i = 0; i < function.arguments_.size(); ++i) {
         arguments[i] = function.arguments_[i]->Accept(*this);
       }
-      return function.function_(arguments, function.arguments_.size(), *ctx_,
-                                dba_);
+      // TODO: Update awesome_memgraph_functions to use the allocator from ctx_
+      return TypedValue(function.function_(
+                            arguments, function.arguments_.size(), *ctx_, dba_),
+                        ctx_->memory);
     } else {
-      std::vector<TypedValue> arguments;
+      TypedValue::TVector arguments(ctx_->memory);
       arguments.reserve(function.arguments_.size());
       for (const auto &argument : function.arguments_) {
         arguments.emplace_back(argument->Accept(*this));
       }
-      return function.function_(arguments.data(), arguments.size(), *ctx_,
-                                dba_);
+      // TODO: Update awesome_memgraph_functions to use the allocator from ctx_
+      return TypedValue(
+          function.function_(arguments.data(), arguments.size(), *ctx_, dba_),
+          ctx_->memory);
     }
   }
-
   TypedValue Visit(Reduce &reduce) override {
     auto list_value = reduce.list_->Accept(*this);
     if (list_value.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     if (list_value.type() != TypedValue::Type::List) {
       throw QueryRuntimeException("REDUCE expected a list, got {}.",
@@ -396,7 +421,7 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
   TypedValue Visit(Extract &extract) override {
     auto list_value = extract.list_->Accept(*this);
     if (list_value.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     if (list_value.type() != TypedValue::Type::List) {
       throw QueryRuntimeException("EXTRACT expected a list, got {}.",
@@ -404,23 +429,23 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
     }
     const auto &list = list_value.ValueList();
     const auto &element_symbol = symbol_table_->at(*extract.identifier_);
-    std::vector<TypedValue> result;
+    TypedValue::TVector result(ctx_->memory);
     result.reserve(list.size());
     for (const auto &element : list) {
       if (element.IsNull()) {
-        result.emplace_back(TypedValue());
+        result.emplace_back();
       } else {
         frame_->at(element_symbol) = element;
         result.emplace_back(extract.expression_->Accept(*this));
       }
     }
-    return TypedValue(result);
+    return TypedValue(result, ctx_->memory);
   }
 
   TypedValue Visit(All &all) override {
     auto list_value = all.list_expression_->Accept(*this);
     if (list_value.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     if (list_value.type() != TypedValue::Type::List) {
       throw QueryRuntimeException("ALL expected a list, got {}.",
@@ -440,13 +465,13 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
         return result;
       }
     }
-    return TypedValue(true);
+    return TypedValue(true, ctx_->memory);
   }
 
   TypedValue Visit(Single &single) override {
     auto list_value = single.list_expression_->Accept(*this);
     if (list_value.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     if (list_value.type() != TypedValue::Type::List) {
       throw QueryRuntimeException("SINGLE expected a list, got {}.",
@@ -468,24 +493,25 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
       }
       // Return false if more than one element satisfies the predicate.
       if (predicate_satisfied) {
-        return TypedValue(false);
+        return TypedValue(false, ctx_->memory);
       } else {
         predicate_satisfied = true;
       }
     }
-    return TypedValue(predicate_satisfied);
+    return TypedValue(predicate_satisfied, ctx_->memory);
   }
 
   TypedValue Visit(ParameterLookup &param_lookup) override {
     return TypedValue(
-        ctx_->parameters.AtTokenPosition(param_lookup.token_position_));
+        ctx_->parameters.AtTokenPosition(param_lookup.token_position_),
+        ctx_->memory);
   }
 
   TypedValue Visit(RegexMatch &regex_match) override {
     auto target_string_value = regex_match.string_expr_->Accept(*this);
     auto regex_value = regex_match.regex_->Accept(*this);
     if (target_string_value.IsNull() || regex_value.IsNull()) {
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     if (regex_value.type() != TypedValue::Type::String) {
       throw QueryRuntimeException(
@@ -496,12 +522,12 @@ class ExpressionEvaluator : public ExpressionVisitor<TypedValue> {
       // Instead of error, we return Null which makes it compatible in case we
       // use indexed lookup which filters out any non-string properties.
       // Assuming a property lookup is the target_string_value.
-      return TypedValue();
+      return TypedValue(ctx_->memory);
     }
     const auto &target_string = target_string_value.ValueString();
     try {
       std::regex regex(regex_value.ValueString());
-      return TypedValue(std::regex_match(target_string, regex));
+      return TypedValue(std::regex_match(target_string, regex), ctx_->memory);
     } catch (const std::regex_error &e) {
       throw QueryRuntimeException("Regex error in '{}': {}",
                                   regex_value.ValueString(), e.what());

src/query/interpreter.cpp

@@ -127,6 +127,8 @@ Callback HandleAuthQuery(AuthQuery *auth_query, auth::Auth *auth,
   Frame frame(0);
   SymbolTable symbol_table;
   EvaluationContext evaluation_context;
+  // TODO: MemoryResource for EvaluationContext, it should probably be passed as
+  // the argument to Callback.
   evaluation_context.timestamp =
       std::chrono::duration_cast<std::chrono::milliseconds>(
           std::chrono::system_clock::now().time_since_epoch())
@@ -421,6 +423,8 @@ Callback HandleStreamQuery(StreamQuery *stream_query,
   Frame frame(0);
   SymbolTable symbol_table;
   EvaluationContext evaluation_context;
+  // TODO: MemoryResource for EvaluationContext, it should probably be passed as
+  // the argument to Callback.
   evaluation_context.timestamp =
       std::chrono::duration_cast<std::chrono::milliseconds>(
           std::chrono::system_clock::now().time_since_epoch())

src/query/interpreter.hpp

@@ -105,6 +105,8 @@ class Interpreter {
           should_abort_query_(should_abort_query) {
       ctx_.is_profile_query = is_profile_query;
       ctx_.symbol_table = plan_->symbol_table();
+      // TODO: Maybe we want a seperate MemoryResource per pull evaluation
+      ctx_.evaluation_context.memory = execution_memory_.get();
       ctx_.evaluation_context.timestamp =
           std::chrono::duration_cast<std::chrono::milliseconds>(
               std::chrono::system_clock::now().time_since_epoch())

tests/benchmark/CMakeLists.txt

@@ -33,6 +33,9 @@ target_link_libraries(${test_prefix}map_concurrent mg-single-node kvstore_dummy_
 add_benchmark(data_structures/ring_buffer.cpp)
 target_link_libraries(${test_prefix}ring_buffer mg-single-node kvstore_dummy_lib)
 
+add_benchmark(query/eval.cpp)
+target_link_libraries(${test_prefix}eval mg-single-node kvstore_dummy_lib)
+
 add_benchmark(query/execution.cpp)
 target_link_libraries(${test_prefix}execution mg-single-node kvstore_dummy_lib)
 

tests/benchmark/query/eval.cpp

@@ -0,0 +1,85 @@
+#include <benchmark/benchmark.h>
+
+#include "query/interpret/eval.hpp"
+
+// The following classes are wrappers for utils::MemoryResource, so that we can
+// use BENCHMARK_TEMPLATE
+
+class MonotonicBufferResource final {
+  utils::MonotonicBufferResource memory_{query::kExecutionMemoryBlockSize};
+
+ public:
+  utils::MemoryResource *get() { return &memory_; }
+};
+
+class NewDeleteResource final {
+ public:
+  utils::MemoryResource *get() { return utils::NewDeleteResource(); }
+};
+
+template <class TMemory>
+// NOLINTNEXTLINE(google-runtime-references)
+static void MapLiteral(benchmark::State &state) {
+  query::AstStorage ast;
+  query::SymbolTable symbol_table;
+  query::Frame frame(symbol_table.max_position());
+  TMemory memory;
+  database::GraphDb db;
+  auto dba = db.Access();
+  std::unordered_map<query::PropertyIx, query::Expression *> elements;
+  for (int64_t i = 0; i < state.range(0); ++i) {
+    elements.emplace(ast.GetPropertyIx("prop" + std::to_string(i)),
+                     ast.Create<query::PrimitiveLiteral>(i));
+  }
+  auto *expr = ast.Create<query::MapLiteral>(elements);
+  query::EvaluationContext evaluation_context{memory.get()};
+  evaluation_context.properties =
+      query::NamesToProperties(ast.properties_, &dba);
+  query::ExpressionEvaluator evaluator(&frame, symbol_table, evaluation_context,
+                                       &dba, query::GraphView::NEW);
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(expr->Accept(evaluator));
+  }
+  state.SetItemsProcessed(state.iterations());
+}
+
+BENCHMARK_TEMPLATE(MapLiteral, NewDeleteResource)
+    ->Range(512, 1U << 15U)
+    ->Unit(benchmark::kMicrosecond);
+
+BENCHMARK_TEMPLATE(MapLiteral, MonotonicBufferResource)
+    ->Range(512, 1U << 15U)
+    ->Unit(benchmark::kMicrosecond);
+
+template <class TMemory>
+// NOLINTNEXTLINE(google-runtime-references)
+static void AdditionOperator(benchmark::State &state) {
+  query::AstStorage ast;
+  query::SymbolTable symbol_table;
+  query::Frame frame(symbol_table.max_position());
+  TMemory memory;
+  database::GraphDb db;
+  auto dba = db.Access();
+  query::Expression *expr = ast.Create<query::PrimitiveLiteral>(0);
+  for (int64_t i = 0; i < state.range(0); ++i) {
+    expr = ast.Create<query::AdditionOperator>(
+        expr, ast.Create<query::PrimitiveLiteral>(i));
+  }
+  query::EvaluationContext evaluation_context{memory.get()};
+  query::ExpressionEvaluator evaluator(&frame, symbol_table, evaluation_context,
+                                       &dba, query::GraphView::NEW);
+  while (state.KeepRunning()) {
+    benchmark::DoNotOptimize(expr->Accept(evaluator));
+  }
+  state.SetItemsProcessed(state.iterations());
+}
+
+BENCHMARK_TEMPLATE(AdditionOperator, NewDeleteResource)
+    ->Range(1024, 1U << 15U)
+    ->Unit(benchmark::kMicrosecond);
+
+BENCHMARK_TEMPLATE(AdditionOperator, MonotonicBufferResource)
+    ->Range(1024, 1U << 15U)
+    ->Unit(benchmark::kMicrosecond);
+
+BENCHMARK_MAIN();

tests/unit/query_expression_evaluator.cpp

@@ -33,12 +33,12 @@ class ExpressionEvaluatorTest : public ::testing::Test {
   database::GraphDbAccessor dba{db.Access()};
 
   AstStorage storage;
-  EvaluationContext ctx;
+  utils::MonotonicBufferResource mem{1024};
+  EvaluationContext ctx{&mem};
   SymbolTable symbol_table;
 
   Frame frame{128};
-  ExpressionEvaluator eval{&frame, symbol_table, ctx, &dba,
-                           GraphView::OLD};
+  ExpressionEvaluator eval{&frame, symbol_table, ctx, &dba, GraphView::OLD};
 
   Identifier *CreateIdentifierWithValue(std::string name,
                                         const TypedValue &value) {
@@ -53,7 +53,11 @@ class ExpressionEvaluatorTest : public ::testing::Test {
   auto Eval(TExpression *expr) {
     ctx.properties = NamesToProperties(storage.properties_, &dba);
     ctx.labels = NamesToLabels(storage.labels_, &dba);
-    return expr->Accept(eval);
+    auto value = expr->Accept(eval);
+    EXPECT_EQ(value.GetMemoryResource(), &mem)
+        << "ExpressionEvaluator must use the MemoryResource from "
+           "EvaluationContext for allocations!";
+    return value;
   }
 };