MemGQL Changelog

MemGQL v0.5.0 - May 16th, 2026

✨ New features & Improvements

Added Oracle connector (CONNECTOR_TYPE=oracle).
DuckDB connector joins as a fifth GQL-over-SQL backend (alongside Memgraph, Neo4j, PostgreSQL, MySQL).
OPTIONAL MATCH now works on SQL backends (PostgreSQL, MySQL, DuckDB) — previously Cypher-only.
WITH pipeline boundary (GQL scope D) on SQL backends — supports WITH, WITH DISTINCT, WITH … ORDER BY … LIMIT N, chained WITH … WITH …, and whole-node WITH n carry-through via derived-table SQL.
UNION / UNION ALL / UNION DISTINCT between query statements work across all five backends. Branches on the same backend translate to that backend’s native combinator; branches on different backends materialize locally and combine in-memory. - Map projections — RETURN n {.id, .title} AS info returns a Bolt Map (Memgraph, Neo4j, PostgreSQL, MySQL, DuckDB).
collect() aggregate returns a typed Bolt List (Memgraph, Neo4j, PostgreSQL, MySQL, DuckDB).
IN list-membership predicate — WHERE n.name IN ['Alice', 'Bob'].
STARTS WITH / ENDS WITH / CONTAINS string predicates portable across all backends.
Quantified path patterns (){m,n} on SQL backends emit a recursive CTE.
MATCH p = (…) RETURN p path binding works on Cypher backends and bounded-path SQL.
Unbounded variable-length paths (()-[*]->()) on SQL backends now return a clear error pointing at the bounded form ((){1,5}) or the Cypher fallback.
SHOW MAPPINGS / SHOW CONNECTORS error messages now hint at the correct setup statements (ADD MAPPING, ADD CONNECTOR).
Untyped edges ()-[]->(b) on SQL backends translate via a UNION ALL over candidate rel-type mappings.

🐞 Bug fixes

INSERT (a {…}) RETURN a.name no longer drops the RETURN clause.
% (modulo) operator now recognized in the grammar and routed through every translator.
PATH_LENGTH(p) on Cypher backends returns the integer length, not the relationship list.
Temporal types (date(...), LOCAL_DATETIME(...), etc.) arrive at the Bolt driver as proper Date / LocalDateTime structs (previously leaked as Rust debug-format strings).
RETURN column headers reflect the source expression text (n.age) instead of the literal placeholder "expr".
RETURN * no longer leaks internal Strategy-B _u / _e placeholders.
SKIP without LIMIT is now honored (was silently dropped).
NULL cells are sent as the PackStream 0xC0 byte (previously the string "NULL").
NULLIF and COALESCE work end-to-end on every backend.
OPTIONAL MATCH WHERE predicates inside the optional pattern land on the correct JOIN clause so unmatched outer rows survive Cypher’s semantics.

MemGQL v0.4.0 - May 7th, 2026

Added “Federated GQL Across Heterogeneous Backends” use case showing graph queries over ClickHouse and PostgreSQL
Added vector search capabilities (only Memgraph backend)
Fixed SET DEFAULT CONNECTION handling
Fixed flaky USE graph behavior and corrected USE graph routing
Fixed multi node and edge SQL INSERT
Fixed connection handling
Improved Trino startup wait
Fixed all tests under run_tests.sh

MemGQL v0.3.0 - April 26th, 2026

Added Apache Pinot connector support, including CONNECTION_TYPE=pinot single mode and multi-connection mode
Added MySQL connector support
Added multi-graph (USE graph …) and composite queries support

MemGQL v0.2.1 - April 17th, 2026

Fixed all required to make the Docker Compose example working as expected

MemGQL v0.2.0 - April 12th, 2026

Added MCP server
Added Clickhouse connector
Added the structured2graph agent to help generate mappings

MemGQL v0.1.0 - March 29th, 2026

GQL parser with ISO/IEC 39075 standard support including quantified path patterns
Federated Bolt server for querying across Neo4j, Memgraph, PostgreSQL, DuckDB, and Iceberg/Trino
GQL-to-native query translation (Cypher for graph DBs, SQL for relational)
Runtime connector management via ADD CONNECTOR, CONNECT, and USE statements
Shortest path queries with ALL SHORTEST, ANY SHORTEST, and SHORTEST k support

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