Postgres

You'll learn how to attach provenance IDs to every unit of context in a RAG or multi-agent pipeline, check model citations, and use Postgres recursive queries to trace a wrong answer back to its source and find everything that came from a document.

This post covers five guardrails you can merge this sprint so the database migrations your coding agent writes don't break during rolling deploys: an N-1 compatibility job, lint output written for the agent, a phase state file, a production read gate, and a one-line CLAUDE.md rule plus a reviewer checklist.

Two writes pretending to be one is the default failure mode of dual-write architectures, and there's a structural fix that makes the drift impossible instead of just rarer.

A 10-minute audit of your actual query pattern — recall, corpus size, filters, writes — will tell you whether you need Pinecone or just Postgres, and for most RAG features the honest answer isn't the one every stack diagram assumes.