Apache Cassandra Vector Search

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.

Open-source distributed SQL database with integrated vector search for storing embeddings alongside relational data, offering strong SQL-based filtering, hybrid search, and high scalability for production RAG and AI applications.

Distributed vector engine for embedding similarity search.

Open-source federated search platform for privacy-preserving vector similarity search across distributed enterprise data sources without data migration or central storage, unlike centralized vector DBs like Pinecone that require uploading all data to a single service. Enables multi-node federation querying 100+ heterogeneous sources simultaneously, using LLM embeddings for re-ranking unified results while keeping data local for enhanced privacy and compliance. Ideal for federated learning scenarios and data-sovereign AI applications.

Crate is an open-source, self-hosted distributed SQL database with native vector data types and similarity search for AI applications. Key features include horizontal scaling, PostgreSQL compatibility, Lucene-based indexing, and Apache 2.0 license. Ideal for RAG and real-time analytics, providing free self-hosting vs managed vector DBs like Pinecone for cost control.

Havenask is an open-source, self-hosted distributed search engine from Alibaba with vector search for large-scale AI applications. Key features include high QPS/TPS, millisecond latency, SQL queries, and free use. Suited for production RAG and search, self-hosted for cost efficiency vs managed like Pinecone.