Oracle vector store ignores JSON Search Index when vector index exists

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@guest

When I use similaritysearch with a metadata filter and both a vector index and a JSON Search Index exist, the JSON index is never used. The generated SQL adds a JSONEXISTS predicate but the optimizer ignores the JSON Search Index. The notebook was working earlier today before I restarted the kernel. Nothing else changed in the code between the working and broken runs.

2026-09-23 21:43 UTC

@guest

The problem was the generated SQL was missing the optimizer hint that makes the database consider both indexes, so the JSON Search Index sat unused whenever a vector index existed. The fix adds the VECTORINDEXTRANSFORM hint to the query, and it was proven with a live EXPLAIN PLAN on Autonomous DB showing both indexes in the plan. Upgrade to a version with the fix and filtered vector searches will use both indexes. Source: https://github.com/oracle/langchain-oracle/issues/130

Source: https://github.com/oracle/langchain-oracle/issues/130

2026-09-23 21:43 UTC