PostgresML

PostgreSQL extension that runs embeddings, vector search, and LLM inference inside your database.

Freemium· Open-source self-host free; managed cloud usage-based with $100 free creditsRAGMulti-model (Llama, Mistral, open-source embeddings)

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Best for

Pick PostgresML if you already run Postgres and want RAG, embeddings, and LLM calls collapsed into one query path instead of four services.

Skip if

Skip it if your stack isn't Postgres-centric or you need bleeding-edge proprietary models like GPT-4 or Claude.

PostgresML turns Postgres into an AI application stack. The PGML extension lets you generate embeddings, run vector similarity search, call open-source LLMs (Llama, Mistral, and friends), do supervised ML (regression, classification, clustering), and even fine-tune models, all from SQL. The companion Korvus SDK exposes the same primitives to Python and JavaScript so application code never has to leave the database boundary.

It's pitched at engineering teams who are tired of stitching a vector DB, an embedding service, an inference API, and a feature store together. By co-locating data and compute, PostgresML avoids the round-trips that dominate RAG latency budgets, and the team benchmarks it as roughly 10x faster than typical retrieval pipelines and ~42% cheaper than Pinecone for vector workloads. You can self-host the open-source extension or use their managed cloud (with VPC options) and $100 in starter credits.

Used in production by Instacart, OneSignal, Alibaba, and VMware. The trade-off is operational: you're now running GPUs and large models next to your OLTP database, which is great for unified architectures but uncomfortable if your DBA team likes Postgres boring.

Editor's take

The cleanest answer to 'why is my RAG pipeline five services and 400ms of latency?' Co-locating vectors and inference with the source data is genuinely the right architecture for a lot of teams, and PostgresML is the most credible implementation of that thesis. Just be honest about the ops cost of mixing GPU workloads with OLTP.

— The AI Tool Bible editorial team