Back to glossary

Vector database

Vektör veritabanı

D3 · Prompts, context, RAG, tools and agents

A vector database stores vector representations and supports retrieving records by vector similarity.

Review status: 2026-12-05

Technical explanation

Vector search can be provided by a dedicated database or an extension to an existing database.

Conceptual boundaries

Storing and searching vectors is different from generating embeddings or generating a final answer.

Provider-neutral example

Illustrative: a document service retrieves records with embeddings close to a query vector for later review.

Limitations

Approximate search can trade recall for speed; vector proximity alone does not establish factual correctness.

Related concepts

Atomic claims and evidence

  1. 1.1Weaviate Database
    Source
    Weaviate Database
    Source role
    Authoritative source
    Exact locator
    What is Weaviate?: objects, embeddings and semantic/hybrid search
    Supported claim
    Weaviate stores and indexes objects with vector embeddings; pgvector adds vector similarity search to Postgres.
    Last verification
    Review due
    Scope limitation
    These are two implementations, not an exhaustive taxonomy of databases.
    1.2pgvector: vector similarity search for Postgres
    Source
    pgvector: vector similarity search for Postgres
    Source role
    Authoritative source
    Exact locator
    README: Storing; Querying; Indexing — exact and approximate nearest neighbor search
    Supported claim
    Weaviate stores and indexes objects with vector embeddings; pgvector adds vector similarity search to Postgres.
    Last verification
    Review due
    Scope limitation
    These are two implementations, not an exhaustive taxonomy of databases.
  2. 2.1pgvector: vector similarity search for Postgres
    Source
    pgvector: vector similarity search for Postgres
    Source role
    Authoritative source
    Exact locator
    README: Storing; Querying; Indexing — exact and approximate nearest neighbor search
    Supported claim
    pgvector documents exact search and approximate indexes that trade recall for speed.
    Last verification
    Review due
    Scope limitation
    This describes pgvector’s search options; no universal ranking of index methods is implied.