CSharpDB v4.0.4

version4.0.4

version4.0.4 adds automatic numeric relationship join acceleration for eligible INNER JOIN queries, restores inline B-tree read performance after the 4.0.3 overflow-page work, reduces reader-session overhead, and resolves the outstanding NU1903 dependency advisories.

Performance

• Broad key-only INNER JOIN queries over a declared INTEGER primary-key-to-foreign-key relationship can now automatically merge-scan the existing foreign-key support index with the parent primary-key tree.
• The supported path is selected conservatively for sufficiently large, unfiltered base-table joins. Text keys, payload projections, predicates or residual conditions, outer and reversed joins, point shapes, and LIMIT/OFFSET retain the existing plan.
• No separate join index or additional payload columns are stored. Inserts, updates, and deletes continue to maintain the existing primary-key and foreign-key indexes.
• Focused SQL comparisons measured 1.84x, 6.77x, and 11.11x faster reads at child fanouts of 1, 10, and 100, with allocations reduced by 53.2% to 94.9%.
• Checkpoint reader tracking now maintains the minimum retained WAL offset incrementally, while no-WAL snapshots reuse an immutable empty page map. Per-query reader-session allocation dropped by 80 bytes in focused testing.

Fixed

• Inline B-tree values now obtain their payload and overflow flag in one leaf-cell parse.
• Point and cursor reads return inline values directly and invoke overflow resolution only for actual overflow references.
• This removes the scan and point-read regression introduced with large-value overflow support while preserving overflow-backed value behavior.

Security and Dependencies

• Pinned Microsoft.OpenApi to 2.7.5.
• Pinned the benchmark and comparative-test SQLite bundle to SQLitePCLRaw.bundle_e_sqlite3 2.1.12.
• The solution vulnerability audit now reports no vulnerable packages and Release builds complete without NU1903 warnings.

Compatibility and Validation

• This release does not introduce a new database format. Existing format-v1 and format-v2 databases retain the compatibility behavior documented for 4.0.3.
• Queries outside the numeric relationship eligibility gates continue through the existing join operators with unchanged SQL semantics.
• Full solution validation passed 2,152 tests with zero failures.
• The complete post-fix release-core run produced all 125 expected rows. Against the published May artifacts, 71 improved by at least 8%, two noisy in-memory hot-set rows regressed by at least 8%, and 52 stayed within the band.
• The full compatible-runner guardrail reported PASS=186, WARN=1, SKIP=0, FAIL=0. A same-session v4.0.3 control reproduced the warned durable-flush slowdown and was 3.2% to 6.4% slower than 4.0.4, isolating the warning to runner/storage drift rather than this release's code.