pgvector in 2024: HNSW Indexes and Real Scaling

pgvector matured in 2023-2024 with the HNSW index type and parallel construction that arrived in version 0.6. For projects already running PostgreSQL, a dedicated vector database is not needed in most cases: this guide explains when PostgreSQL is enough, how to configure the index, and where it starts to fall short.

January 21, 2024 7 min 259 4.4

Architecture

pgvector: Semantic Search Without Leaving Postgres

pgvector turns PostgreSQL into a vector database without adding another service to the stack. With version 0.8.6 and PostgreSQL 18, HNSW reached 95.1% recall@10 at 1.15 ms on 99,000 real embeddings. SQL filters share the query with vector ranking, and iterative index scans stop a filter from returning fewer rows than requested.

November 1, 2023 13 min 252