The Postgres Developer's Guide to Vector Index Tradeoffs (opens in new tab)

Vector search in Postgres isn't about choosing the best ANN algorithm—it's about choosing the right index for your constraints. This guide explains when to use exact search, HNSW, IVFFlat, StreamingDiskANN, and BM25-based hybrid search based on memory, recall, write volume, and filter selectivity. Learn how pgvector, pgvectorscale, and pg_textsearch fit together as workloads scale.