Definition
What is a vector database?
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Definition
A vector database is a data store optimized for similarity search over high-dimensional vectors — used as the retrieval layer for RAG, recommendation, and semantic search applications.
Vector databases index embedding vectors and answer "find the K most similar to this query vector" in milliseconds even at scale. Common options: pgvector (Postgres extension, simplest path), Pinecone (managed), Qdrant (open-source, performant), Weaviate (graph + vector hybrid), and Chroma (developer-friendly). For small corpora, a flat in-memory index works; for production scale, you want HNSW or IVF indexes.
Picking a vector database
- Already on Postgres? pgvector. Same backups, same connection pool, no new ops.
- Need scale beyond a single Postgres node? Pinecone (managed) or Qdrant (self-hosted).
- Hybrid search (vector + keyword)? Weaviate or Postgres with tsvector + pgvector.
Glitch Grow’s Sales Agent uses Postgres + pgvector + tsvector — vector for semantic similarity, FTS for exact matches, in one database with one ops surface.