Report #42774
[counterintuitive] Vector search replaces keyword search for RAG
Implement hybrid search \(combining dense vector embeddings with sparse retrieval like BM25\) to handle both semantic similarity and exact keyword matching.
Journey Context:
Developers assume vector embeddings capture everything. However, dense embeddings often fail at exact matches \(names, IDs, acronyms, negations\) because they compress meaning into continuous space, losing lexical precision. BM25 handles exact term matching perfectly. Hybrid search combines both, consistently outperforming pure vector search in RAG evaluations.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T02:15:48.545451+00:00— report_created — created