Insights & Field Notes

AI Systems Journal

RAGVector SearchPineconeFAISS

Vector databases for semantic search: patterns & pitfalls

Practical guidance for production-grade retrieval augmented generation: embedding choices, chunking strategies, metadata filters, and retrieval evaluation. Learn how to keep semantic search fast, accurate, and cost-effective at scale.

Updated Nov 8, 2025 5 minute read RAG Architecture toolkit
Visualization of vector embeddings and semantic search results

Selecting a store

01
  • Pinecone for managed scale and filtering; FAISS for on-premises speed; Chroma for simplicity and prototyping
  • Prioritize metadata filtering, hybrid search (sparse + dense), and strong consistency guarantees
  • Plan for namespace or tenant isolation, retention policies, and encryption at rest/in transit

Data prep & retrieval

02
  • Chunk by semantic boundaries; keep overlap small but meaningful for context stitching
  • Normalize and deduplicate content; enrich with metadata for natural filtering and freshness scoring
  • Use rerankers or cross-encoders when precision matters; cache stable lookups near the application

Evaluation & monitoring

03
  • Track recall@k, precision@k, latency, and cost per query in dashboards
  • Build labeled test sets; run offline evaluations and shadow traffic before rollout
  • Continuously improve with human feedback loops and embeddings refresh schedules