May 2026 product summary for lancedb/lance focused on reliability for stable-row-id handling. Implemented a critical correctness fix to the deletion mask by restricting it to fragments within the fragment bitmap, preventing duplicates during merge_insert and avoiding inaccurate full-text search results. Introduced mechanisms to propagate fragment-restrictions through prefilter, added an optional restrict_hash to RowAddrMaskKey to keep per-subset caches isolated, and refined caching to avoid cross-contamination. Added regression tests for restricted deletion masks, repeated merge_insert with stable row IDs, and FTS duplicates. Achieved strong test results and clean tooling checks: prefilter tests 18/18, merge_insert tests 145/145; cargo fmt and clippy linting passing. This work reduces data duplication, improves merge reliability, and enhances search accuracy, boosting data integrity and user trust. Technologies involved include Rust, RoaringBitmap, prefilter logic, cache key design, and regression testing with cargo tooling.