Handle missing HNSW ids in filtered local query

[Raditya0902]

Description of changes

• Improvements & Bug fixes

  • Fixes a local query edge case where query(where=...) could fail with Error finding id ... when a metadata-filtered candidate exists in metadata/WAL state but is missing from the HNSW reader/index mapping after cache reload.
  • Skips IdNotFound candidates only in the metadata-filtered local KNN path.
  • Preserves unfiltered and id-only query behavior.
  • Returns an empty KNN result when all filtered candidates are missing from HNSW.
  • Adds a regression test for the cache-reload/missing-candidate case.

• New functionality

  • None.

Fixes #7032.

Test plan

• Tests pass locally with pytest for python, yarn test for js, cargo test for rust

Tested with:

cargo test -p chroma-frontend test_query_where_skips_hnsw_missing_candidate_after_cache_reload
cargo test -p chroma-frontend local

[github-actions]

Reviewer Checklist

Please leverage this checklist to ensure your code review is thorough before approving

Testing, Bugs, Errors, Logs, Documentation

• Can you think of any use case in which the code does not behave as intended? Have they been tested?
• Can you think of any inputs or external events that could break the code? Is user input validated and safe? Have they been tested?
• If appropriate, are there adequate property based tests?
• If appropriate, are there adequate unit tests?
• Should any logging, debugging, tracing information be added or removed?
• Are error messages user-friendly?
• Have all documentation changes needed been made?
• Have all non-obvious changes been commented?

System Compatibility

• Are there any potential impacts on other parts of the system or backward compatibility?
• Does this change intersect with any items on our roadmap, and if so, is there a plan for fitting them together?

Quality

• Is this code of a unexpectedly high quality (Readability, Modularity, Intuitiveness)

[propel-code-bot]

Fix local filtered KNN queries when metadata candidates are missing in HNSW mapping

This PR fixes a local query edge case in rust/frontend/src/executor/local.rs where query(where=...) could fail with an IdNotFound-style error if metadata-filtered IDs exist in metadata/WAL but are missing from the HNSW reader mapping (for example after cache reload/reset). The knn path now conditionally tolerates missing HNSW IDs only for metadata-filtered execution, while preserving prior behavior for unfiltered and ID-only queries.

The change introduces a skip_missing_hnsw_ids control flag tied to filter mode, updates offset-ID resolution to skip only LocalHnswSegmentReaderError::IdNotFound in that scoped path, and returns an empty KNN result when all filtered candidates are skipped. A targeted regression test reproduces the cache-reload scenario and validates non-error empty-result behavior.

This summary was automatically generated by @propel-code-bot

[propel-code-bot]

Review found no issues; the edge-case handling and regression coverage appear sound.

Status: No Issues Found | Risk: Low

Review Details

📁 1 files reviewed | 💬 0 comments

Instruction Files

├── AGENTS.md
└── CLAUDE.md