v1.0.22 - Query Shapes + Cartesian performance

[v1.0.22] - 2026-03-19

Added

• Expanded Cypher regression coverage:
  • added targeted tests for correlated UNWIND + multi-MATCH execution routing
  • added stability tests for MATCH ... CREATE ... RETURN count(*) cardinality and idempotent behavior.

Changed

• MATCH...CREATE join execution hot path:
  • added join-aware combination building for N-variable equality-join shapes to avoid unnecessary cartesian expansion
  • improved selective pushdown behavior for IN + equality predicates before combination building.
• UNWIND correlated rewrite routing:
  • preserved correlation semantics in rewrite transforms so value-bucket joins do not degrade into cross-key cartesian behavior.

Fixed

• Aggregation row-shape correctness: Fixed edge cases where aggregation-only RETURN count(*) could produce an empty rowset instead of a single deterministic row.
• MATCH/WHERE context handling: Fixed multi-variable WHERE handling in MATCH...CREATE paths so per-node filters are only applied when semantically valid and cross-variable predicates are evaluated in the correct phase.
• Relationship existence filter handling: Fixed NOT (a)-[:TYPE]->(b) handling in post-filter execution so write guards remain correct under batched correlated joins.

Tests

• Added deterministic tests for:
  • dual-side IN join-filtered MATCH...CREATE write paths
  • join-aware combination builder correctness for multi-variable equality joins
  • correlated UNWIND + multi-MATCH execution routing and count semantics.
• Expanded Fabric/Cypher targeted regression validation around direct context matching and correlated execution behavior.

Technical Details

• Range covered: v1.0.20..HEAD
• Commits in range: 3 (non-merge)
• Repository delta: 15 files changed, +2,799 / -116 lines
• Primary focus areas: Cypher write-path reliability, correlated UNWIND routing correctness, MATCH...CREATE join-path performance, and aggregation result-shape determinism.