Milvus vs Vespa

Milvus is an open-source vector database from Zilliz for GenAI and scalable vector search. It supports approximate-nearest-neighbor, filtered, range, hybrid, and full-text search, along with reranking, fetch, and query operations. Metadata filtering, sparse vectors, and index types including HNSW, IVF, FLAT, DiskANN, and SCANN are documented. Deployment choices are Milvus Lite as a Python library, Standalone as a single-machine server, and Distributed on Kubernetes. Documentation recommends Lite for up to a few million vectors, Standalone up to 100 million, and Distributed for 100 million to tens of billions. Lite can run locally without a cloud service for private or sensitive data; an online upgrade from Standalone to a cluster is not currently supported. Official interfaces include REST plus Python, Go, Java, Node.js, and C++ APIs or SDKs. C# is contributed by Microsoft and Rust is under development. Security documentation covers authentication, TLS for gRPC and REST, and role-based access control at collection, database, and instance levels. The Apache 2.0 software is free, and Zilliz Cloud is offered as a managed option.

Vespa is an AI search platform for online applications that use data, retrieval, ranking, machine-learning inference, and real-time serving. It supports vector and tensor search, positional text search, and queries over structured data. Ranking signals can be combined with tensor functions or machine-learned models, including ONNX and XGBoost formats; model inference can use ONNX Runtime. Vespa distributes functions across node clusters and allows cluster size changes without affecting queries or writes. Teams can self-manage deployments, use the Vespa Kubernetes Operator, or run on Vespa Cloud. Local deployment guidance lists Linux, macOS, and Windows 10 Pro on x86_64 or arm64 with Docker Desktop or Podman Desktop. Vespa Cloud includes encryption at rest and in transit, certificates for nodes and endpoints, and automatic operating system patching. Its trial provides $300 in credits without requiring a credit card, then stops the application when credits are used. Cloud plans have quotas, and Startup is limited to development zones. Pricing is listed from $0.05 a month, with metered resource rates.