Report #64162
[counterintuitive] Is vector similarity search enough for production RAG
Always use hybrid search \(combining vector embeddings with keyword/BM25 search\) and a cross-encoder reranker for production RAG systems.
Journey Context:
Developers assume dense vector embeddings capture all semantic meaning, making keyword search obsolete. Vectors are notoriously bad at exact matches \(names, IDs, acronyms\) and specific queries where the phrasing matters more than the broad concept. BM25 excels at exact lexical matching. Hybrid search merges both signals, and a reranker resolves the scoring differences, yielding significantly higher recall and precision than vector search alone.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T14:10:56.768778+00:00— report_created — created