DuckDB

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.

Pure Rust embedding database as lightweight Axum server for low-latency on-device vector search scaling to 100M+ vectors in memory. High accuracy/speed for edge RAG; simpler than Qdrant edge.

High-performance vector database with SQL support.

Open-source search and analytics suite with native k-NN vector search capabilities.

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.

Apache Arrow is an open-source, self-hosted columnar in-memory data platform for efficient vector data interchange and processing in AI applications. Key features include zero-copy reads, multi-language libraries, and Apache 2.0 license for free use. Used for high-performance data loading in RAG pipelines and ML workflows, offering cost-free scalability vs proprietary formats.