Apache Iceberg Delivers Data Portability, Not Full Vendor Lock-in Freedom

Apache Iceberg, the open table format widely adopted across platforms like AWS, Databricks, Snowflake, and Microsoft Fabric, has significantly improved data portability by opening up file formats, metadata management, and access APIs that were previously locked within proprietary services. The format stores schemas, snapshots, and partition specs in open metadata files backed by standard storage like Parquet and S3, making the data layer largely interoperable. However, the Iceberg spec does not standardize the atomic commit mechanism used to swap metadata pointers, leaving that responsibility to individual catalog implementations. The REST Catalog Protocol was introduced to create a common API across languages and engines, shifting commit responsibility from the client to the server, but it leaves authorization models — such as access control and permission structures — undefined. Real-world catalog products fill this gap with proprietary features like row- and column-level security, data discovery, and lineage tracking, which remain a source of vendor dependency.