Multi-Engine Catalog Federation with Apache Polaris: Syncing Google Cloud, AWS, and Azure Metadata

This article discusses the challenge of catalog lock-in in modern data lakehouse architectures and how Apache Polaris addresses it by enabling open table governance across multiple clouds and query engines. It covers key aspects such as identity and role mapping, storage credentials, namespace design, and multi-engine write contracts. The author emphasizes that federation differs from replication and provides practical guidance for operating a federated catalog, including a checklist, common pitfalls, and operating rules. The piece positions Polaris as part of a broader movement toward open catalog governance, benefiting tools like Dremio by separating open data, query federation, and governed access from proprietary boundaries.