Vector Database Performance Compared: pgvector vs Pinecone vs Qdrant vs Weaviate

Every team building search or RAG eventually asks the same question: which vector database should we use? I've spent the last year working with pgvector in production (it's what powers Vecstore under the hood) and I've tested most of the alternatives. Here's what the benchmarks actually show. The Databases Quick overview of what we're comparing: pgvector is a Postgres extension. You add vector search to your existing database. No separate service, no sync layer, no new infrastructure. The tradeoff is that Postgres wasn't built for vector search, so performance at very large scale takes more tuning. Pinecone is a managed vector database. You push vectors in, query them out. No infrastructure to manage. The tradeoff is cost and the fact that it's a separate system from your application database. Qdrant is an open-source vector database you can self-host or use their cloud. Written in Rust, built specifically for vector search. Strong filtered search performance. Weaviate is another open-