pgvector — #1 Alternative to Pinecone
Open-source vector similarity search inside PostgreSQL with full ACID joins and HNSW indexes
pgvector (paired with pgvectorscale DiskANN when scaling to 50M+ vectors) stores embeddings right alongside relational user permissions and metadata—eliminating dual-write sync pipelines entirely.
License: PostgreSQL License · Pricing: Free & Open Source · Compare all Pinecone alternatives · Official Website