Apache Cassandra is a distributed NoSQL database that is adding native support for high-dimensional vector storage and approximate nearest neighbor search, making it a scalable choice for AI and vector search workloads.

Milvus Distributed is the cluster mode of the scalable open-source vector database for AI embeddings search, supporting HNSW, IVF, and NGT indexes in high-availability distributed setups. It provides GPU support, billion-scale capacity, real-time upsert/query capabilities, and multi-modal vector handling. Suited for RAG, recommendations, and image/video search at enterprise scale. Self-hosted unlike Pinecone's managed offering, and more ANN-centric than Weaviate.

CoTra system by Zhi et al. for efficient distributed vector search using RDMA. Published in SIGMOD 2026 proceedings.

A research paper on accuracy-preserving index construction for distributed vector search systems. Published in 2025, it addresses the challenge of maintaining search quality while distributing vector indexes across multiple nodes.

Open-source distributed graph database designed for super large-scale graphs with billions of vertices and trillions of edges. Outperforms Neo4j on larger datasets while providing graph database capabilities for AI applications.

SPTAG is a distributed approximate nearest neighbor (ANN) library for building and searching large-scale vector indexes, supporting efficient and scalable vector search scenarios.