Vector databases are the unsung heroes of the AI stack. They enable semantic search, recommendations, and RAG — making LLMs truly useful.
What Are Vector Databases?
They store embeddings — high-dimensional vectors capturing semantic meaning of text, images, or audio.
Why They Matter
LLMs only know training data. Vector DBs connect LLMs to your proprietary data through RAG.
Leading Platforms
Pinecone
Managed, serverless. Auto-scaling, free tier. Best without DevOps overhead.
Weaviate
Open-source with hybrid search (vector + keyword). Self-host or cloud.
Qdrant
Written in Rust. Blazing fast. Filtering, payload indexing, multi-tenancy.
PGVector
PostgreSQL extension. Simplest path if already on Postgres.
Use Cases
- Semantic search: Search by meaning
- RAG: Grounded LLM responses
- Recommendations: Similar items
- Anomaly detection: Unusual patterns

