TL;DR

LanceDB specializes in end-to-end ML workflows with integrated data curation, feature engineering via Python UDFs, and direct training capabilities (70% MFU), making it a comprehensive lakehouse solution. Milvus focuses purely on vector search performance and scalability, offering proven horizontal scaling to tens of billions of vectors with flexible deployment options and stronger ecosystem integration through its open-source Apache 2.0 license. Choose LanceDB if you need an all-in-one data preparation and training platform; choose Milvus if you need battle-tested, production-grade vector search with extensive community support and deployment flexibility.