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Vector database

What is a vector database?

A vector database is a database designed to store embeddings and quickly find the ones most similar to a query, a task called similarity or nearest-neighbor search. It is the usual storage layer behind semantic search and retrieval-augmented generation. Dedicated products exist, and many standard databases, including PostgreSQL with the pgvector extension, now offer the same capability.

01why it matters for a business

Vendors sometimes present the vector database as the heart of an AI project. It is usually a supporting component. The decision that matters is whether your existing data platform can handle vector search at your scale, which it often can, versus adding a new system your team has to secure, back up, and pay for. Fewer moving parts generally means fewer failures and simpler compliance.

What matters more than the product choice is what goes into it: which content is indexed, how it is split, what metadata travels with each item (source, date, owner, access level), and how the index stays in sync when documents change or are deleted. Stale or orphaned vectors are a common source of wrong answers and, with sensitive data, of compliance trouble.

02what it looks like in practice

A mid-sized insurer already runs PostgreSQL for its policy administration system. For an internal assistant over underwriting guidelines, it adds the pgvector extension and stores embeddings alongside each guideline's metadata. Access rules come from existing tables, so an underwriter's search only returns guidelines for their lines of business. A nightly job re-embeds changed documents and deletes vectors for retired ones. No new database vendor was needed.

03common mistakes

04related terms

05where insomnia club fits

Insomnia Club designs retrieval storage around the data platform you already run where possible, with metadata, permissions, and sync built in from the start.

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