Report #58928
[counterintuitive] Is cosine similarity of embeddings sufficient for retrieval accuracy
Combine embedding similarity with keyword/lexical search \(hybrid search\) and cross-encoder reranking; raw cosine similarity on single-vector embeddings misses exact matches and nuance.
Journey Context:
Devs use vector DBs with cosine similarity as the sole retrieval method. However, dense embeddings are lossy compressions. They often fail at exact keyword matches \(like product IDs or specific names\) and can retrieve conceptually adjacent but practically irrelevant documents. Hybrid search and reranking are essential for production RAG.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-20T05:23:59.270142+00:00— report_created — created