memgraph/CHANGELOG.md

Change Log

v1.0.0

Major Features and Improvements

• [Enterprise Ed.] Exposed authentication username/rolename regex as a flag (--auth-user-or-role-name-regex).
• [Enterprise Ed.] Improved auth module error handling and added support for relative paths.
• Added support for Python query modules. This release of Memgraph supports query modules written using the already existing C API and the new Python API.
• Added support for unique constraints. The unique constraint is created with a label and one or more properties.
• Implemented support for importing CSV files (mg_import_csv). The importer is compatible with the Neo4j batch CSV importer.
• Snapshot and write-ahead log format changed (backward compatible with v0.50).
• Vertices looked up by their openCypher ID (MATCH (n) WHERE ID(n) = ...) will now find the node in O(logn) instead of O(n).
• Improved planning of BFS expansion, a faster, specific approach is now favored instead of a ScanAll+Filter operation.
• Added syntax for limiting memory of CALL.
• Exposed server name that should be used for Bolt handshake as flag (--bolt-server-name-for-init).
• Added several more functions to the query module C API.
• Implemented a storage locking mechanism that prevents the user from concurrently starting two Memgraph instances with the same data directory.

Bug Fixes and Other Changes

• [Enterprise Ed.] Fixed a bug that crashed the database when granting privileges to a user.
• [Enterprise Ed.] Improved Louvain algorithm for community detection.
• Type of variable expansion is now printed in EXPLAIN (e.g. ExpandVariable, STShortestPath, BFSExpand, WeightedShortestPath).
• Correctly display CALL in EXPLAIN output.
• Correctly delimit arguments when printing the signature of a query module.
• Fixed a planning issue when CALL preceded filtering.
• Fixed spelling mistakes in the storage durability module.
• Fixed storage GC indices/constraints subtle race condition.
• Reduced memory allocations in storage API and indices.
• Memgraph version is now outputted to stdout when Memgraph is started.
• Improved RPM packaging.
• Reduced number of errors reported in production log when loading query modules.
• Removed early access wording from the Community Offering license.

v0.50.0

Breaking Changes

• [Enterprise Ed.] Remove support for Kafka streams.
• Snapshot and write-ahead log format changed (not backward compatible).
• Removed support for unique constraints.
• Label indices aren't created automatically, create them explicitly instead.
• Renamed several database flags. Please see the configuration file for a list of current flags.

Major Features and Improvements

• [Enterprise Ed.] Add support for auth module.
• [Enterprise Ed.] LDAP support migrated to auth module.
• Implemented new graph storage engine.
• Add support for disabling properties on edges.
• Add support for existence constraints.
• Add support for custom openCypher procedures using a C API.
• Support loading query modules implementing read-only procedures.
• Add CALL <procedure> YIELD <result> syntax for invoking loaded procedures.
• Add CREATE INDEX ON :Label for creating label indices.
• Add DROP INDEX ON :Label for dropping label indices.
• Add DUMP DATABASE clause to openCypher.
• Add functions for treating character strings as byte strings.

Bug Fixes and Other Changes

• Fix several memory management bugs.
• Reduce memory usage in query execution.
• Fix bug that crashes the database when EXPLAIN is used.

v0.15.0

Breaking Changes

• Snapshot and write-ahead log format changed (not backward compatible).
• indexInfo() function replaced with SHOW INDEX INFO syntax.
• Removed support for unique index. Use unique constraints instead.
• CREATE UNIQUE INDEX ON :label (property) replaced with CREATE CONSTRAINT ON (n:label) ASSERT n.property IS UNIQUE.
• Changed semantics for COUNTER openCypher function.

Major Features and Improvements

• [Enterprise Ed.] Add new privilege, STATS for accessing storage info.
• [Enterprise Ed.] LDAP authentication and authorization support.
• [Enterprise Ed.] Add audit logging feature.
• Add multiple properties unique constraint which replace unique indices.
• Add SHOW STORAGE INFO feature.
• Add PROFILE clause to openCypher.
• Add CREATE CONSTRAINT clause to openCypher.
• Add DROP CONSTRAINT clause to openCypher.
• Add SHOW CONSTRAINT INFO feature.
• Add uniformSample function to openCypher.
• Add regex matching to openCypher.

Bug Fixes and Other Changes

• Fix bug in explicit transaction handling.
• Fix bug in edge filtering by edge type and destination.
• Fix bug in query comment parsing.
• Fix bug in query symbol table.
• Fix OpenSSL memory leaks.
• Make authentication case insensitive.
• Remove COALESCE function.
• Add movie tutorial.
• Add backpacking tutorial.

v0.14.0

Breaking Changes

• Write-ahead log format changed (not backward compatible).

Major Features and Improvements

• [Enterprise Ed.] Reduce memory usage in distributed usage.
• Add DROP INDEX feature.
• Improve SSL error messages.

Bug Fixes and Other Changes

• [Enterprise Ed.] Fix issues with reading and writing in a distributed query.
• Correctly handle an edge case with unique constraint checks.
• Fix a minor issue with mg_import_csv.
• Fix an issue with EXPLAIN.

v0.13.0

Breaking Changes

• Write-ahead log format changed (not backward compatible).
• Snapshot format changed (not backward compatible).

Major Features and Improvements

• [Enterprise Ed.] Authentication and authorization support.
• [Enterprise Ed.] Kafka integration.
• [Enterprise Ed.] Support dynamic worker addition in distributed.
• Reduce memory usage and improve overall performance.
• Add CREATE UNIQUE INDEX clause to openCypher.
• Add EXPLAIN clause to openCypher.
• Add inDegree and outDegree functions to openCypher.
• Improve BFS performance when both endpoints are known.
• Add new node-label, relationship-type and quote options to mg_import_csv tool.
• Reduce memory usage of mg_import_csv.

Bug Fixes and Other Changes

• [Enterprise Ed.] Fix an edge case in distributed index creation.
• [Enterprise Ed.] Fix issues with Cartesian in distributed queries.
• Correctly handle large messages in Bolt protocol.
• Fix issues when handling explicitly started transactions in queries.
• Allow openCypher keywords to be used as variable names.
• Revise and make user visible error messages consistent.
• Improve aborting time consuming execution.

v0.12.0

Breaking Changes

• Snapshot format changed (not backward compatible).

Major Features and Improvements

• Improved Id Cypher function.
• Added string functions to openCypher (lTrim, left, rTrim, replace, reverse, right, split, substring, toLower, toUpper, trim).
• Added timestamp function to openCypher.
• Added support for dynamic property access with [] operator.

v0.11.0

Major Features and Improvements

• [Enterprise Ed.] Improve Cartesian support in distributed queries.
• [Enterprise Ed.] Improve distributed execution of BFS.
• [Enterprise Ed.] Dynamic graph partitioner added.
• Static nodes/edges id generators exposed through the Id Cypher function.
• Properties on disk added.
• Telemetry added.
• SSL support added.
• toString function added.

Bug Fixes and Other Changes

• Document issues with Docker on OS X.
• Add BFS and Dijkstra's algorithm examples to documentation.

v0.10.0

Breaking Changes

• Snapshot format changed (not backward compatible).

Major Features and Improvements

• [Enterprise Ed.] Distributed storage and execution.
• reduce and single functions added to openCypher.
• wShortest edge expansion added to openCypher.
• Support packaging RPM on CentOS 7.

Bug Fixes and Other Changes

• Report an error if updating a deleted element.
• Log an error if reading info on available memory fails.
• Fix a bug when MATCH would stop matching if a result was empty, but later results still contain data to be matched. The simplest case of this was the query: UNWIND [1,2,3] AS x MATCH (n :Label {prop: x}) RETURN n. If there was no node (:Label {prop: 1}), then the MATCH wouldn't even try to find for x being 2 or 3.
• Report an error if trying to compare a property value with something that cannot be stored in a property.
• Fix crashes in some obscure cases.
• Commit log automatically garbage collected.
• Add minor performance improvements.

v0.9.0

Breaking Changes

• Snapshot format changed (not backward compatible).
• Snapshot configuration flags changed, general durability flags added.

Major Features and Improvements

• Write-ahead log added.
• nodes and relationships functions added.
• UNION and UNION ALL is implemented.
• Concurrent index creation is now enabled.

Bug Fixes and Other Changes

v0.8.0

Major Features and Improvements

• CASE construct (without aggregations).
• Named path support added.
• Maps can now be stored as node/edge properties.
• Map indexing supported.
• rand function added.
• assert function added.
• counter and counterSet functions added.
• indexInfo function added.
• collect aggregation now supports Map collection.
• Changed the BFS syntax.

Bug Fixes and Other Changes

• Use \u to specify 4 digit codepoint and \U for 8 digit
• Keywords appearing in header (named expressions) keep original case.
• Our Bolt protocol implementation is now completely compatible with the protocol version 1 specification. (https://boltprotocol.org/v1/)
• Added a log warning when running out of memory and the memory_warning_threshold flag
• Edges are no longer additionally filtered after expansion.

v0.7.0

Major Features and Improvements

• Variable length path MATCH.
• Explicitly started transactions (multi-query transactions).
• Map literal.
• Query parameters (except for parameters in place of property maps).
• all function in openCypher.
• degree function in openCypher.
• User specified transaction execution timeout.

Bug Fixes and Other Changes

• Concurrent BUILD INDEX deadlock now returns an error to the client.
• A MATCH preceeded by OPTIONAL MATCH expansion inconsistencies.
• High concurrency Antlr parsing bug.
• Indexing improvements.
• Query stripping and caching speedups.

v0.6.0

Major Features and Improvements

• AST caching.
• Label + property index support.
• Different logging setup & format.

v0.5.0

Major Features and Improvements

• Use label indexes to speed up querying.
• Generate multiple query plans and use the cost estimator to select the best.
• Snapshots & Recovery.
• Abandon old yaml configuration and migrate to gflags.
• Query stripping & AST caching support.

Bug Fixes and Other Changes

• Fixed race condition in MVCC. Hints exp+aborted race condition prevented.
• Fixed conceptual bug in MVCC GC. Evaluate old records w.r.t. the oldest. transaction's id AND snapshot.
• User friendly error messages thrown from the query engine.

Build 837

Bug Fixes and Other Changes

• List indexing supported with preceeding IN (for example in query RETURN 1 IN [[1,2]][0]).

Build 825

Major Features and Improvements

• RETURN , count(), OPTIONAL MATCH, UNWIND, DISTINCT (except DISTINCT in aggregate functions), list indexing and slicing, escaped labels, IN LIST operator, range function.

Bug Fixes and Other Changes

• TCP_NODELAY -> import should be faster.
• Clear hint bits.

Build 783

Major Features and Improvements

• SKIP, LIMIT, ORDER BY.
• Math functions.
• Initial support for MERGE clause.

Bug Fixes and Other Changes

• Unhandled Lock Timeout Exception.

Build 755

Major Features and Improvements

• MATCH, CREATE, WHERE, SET, REMOVE, DELETE.