This article breaks down leading open source vector databases, comparing their indexing methods, hybrid search support, deployment options, and integrations with caching or operational data. It highlights trade-offs for production AI workloads—from Redis’s unified real-time platform to specialized tools like Milvus, Weaviate, Qdrant, Chroma, pgvector, and Faiss.

• Redis Search hits 90% precision at 200ms median latency (top-100, 50 concurrent queries, up to 66K inserts/sec), but 95% precision costs ~1.3s latency.
• Redis positions itself as a unified layer replacing the separate vector store + cache + operational DB stack that Milvus, Weaviate, Qdrant, Chroma, pgvector, and Faiss all require.
• Redis LangCache/Iris semantic caching reportedly cuts LLM inference calls by ~70% in high-traffic setups.
• Specialized tools each have a niche: Milvus for billion-vector Kubernetes deployments, Weaviate for native hybrid search/GraphQL, Qdrant for Rust-based filtering, Chroma for local prototyping, pgvector for Postgres integration, Faiss for custom C++ infra.