Backport #168: Fix zero scores when querying hypertables#175
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tjgreen42 merged 2 commits intorelease/0.4.2from Jan 25, 2026
Merged
Backport #168: Fix zero scores when querying hypertables#175tjgreen42 merged 2 commits intorelease/0.4.2from
tjgreen42 merged 2 commits intorelease/0.4.2from
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The planner hook's plan_has_bm25_indexscan() and replace_scores_in_plan() functions didn't handle CustomScan nodes (like TimescaleDB's ConstraintAwareAppend). This caused the hook to miss BM25 index scans nested inside custom scans, so score expressions weren't replaced with stub functions that retrieve cached scores from the index scan. As a result, standalone scoring was used instead, which looked up the parent hypertable index (which has total_docs = 0), producing zero scores for all results. The fix adds T_CustomScan cases that recurse into cscan->custom_plans to properly detect and process BM25 index scans.
When using standalone BM25 scoring on a hypertable with the parent index
name (e.g., `content <@> to_bm25query('database', 'parent_idx')`), the
code was falling back to child index stats (total_docs, avg_doc_len) but
NOT switching to the child's index relation and segment metadata. This
caused IDF calculation to fail because it was looking up document
frequencies in the parent index's segments (which are empty).
The fix switches to the child index for segment access when falling back
to a child index's state. This ensures that both memtable and segment
lookups use the correct child index.
Also adds:
- Test 5 in partitioned.sql for MergeAppend score expression replacement
- test/scripts/hypertable.sh for optional TimescaleDB integration testing
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Summary
Backport of #168 to the 0.4.2 release branch.
Fixes zero scores when querying hypertables with BM25 indexes:
Planner hook fix for CustomScan - Add
T_CustomScanhandling inplan_has_bm25_indexscan()to detect BM25 index scans nested inside custom scans (e.g., TimescaleDB's ConstraintAwareAppend)Standalone scoring fix for hypertable parent indexes - When using standalone BM25 scoring with a hypertable parent index name, the code was falling back to child index stats but NOT switching to the child's index relation and segment metadata
Testing
Cherry-picked from main where it passed all CI checks.