Report #72156
[counterintuitive] Is vector similarity search enough for RAG retrieval
Combine vector search with keyword/lexical search \(Hybrid Search\) and implement reranking \(e.g., cross-encoders\) to improve retrieval precision.
Journey Context:
Developers build RAG pipelines relying solely on dense vector embeddings \(cosine similarity\). Embeddings capture semantic similarity but often miss exact keyword matches \(names, IDs, specific acronyms\) and suffer from semantic flattening where broad concepts overpower specific nuances. Hybrid search \(BM25 \+ vectors\) captures both, and a reranker resolves the final ordering.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-21T03:41:50.191194+00:00— report_created — created