BitByteCore Software Desk

Vector Databases: How They Actually Work, and When You Don't Need One

A vector database does three plain things: store embeddings, index them, and answer "what's closest?" fast. Here's how that machinery really works — similarity metrics, HNSW and IVF indexes, quantization, filtering — and the many cases where Postgres already does the job.

BitByteCore Software Desk · Aug 7, 2026 · 4 min read