OpenSearch

ClickHouse is a columnar OLAP database with vector indexes (ANN via AMM, brute-force), supporting SQL queries over vectors + structured data at petabyte scale. Excels in aggregations with vectors. For analytics workloads with embeddings; faster ingestion than Postgres pgvector for big data.

Embeddable SQL OLAP engine with VSS extension for low-latency HNSW vector search on local files, ideal for edge AI prototyping and analytics. SQL-first approach for on-device vector ops vs cloud vector DBs like Qdrant.

Open-source high-performance analytical database with vector search capabilities. Features IVFPQ and HNSW indexing for approximate nearest neighbor search in v3.4+. This is an OSS database under Apache 2.0, a Linux Foundation project.

Trieve provides an all-in-one infrastructure for vector search, recommendations, retrieval-augmented generation (RAG), and analytics, accessible via API for seamless integration.

Open-source multi-model database with native vector embedding support alongside graph, document, and more.

Cottontail DB is a column store aimed at multimedia retrieval, allowing classical boolean as well as vector-space retrieval (nearest neighbour search) using a unified data and query model.