Apache Iceberg 1.12.0 drops Spark 3.4 support and expands engine features

Apache Iceberg 1.12.0 arrived September 30, 2026, and the release guide lists more than 800 merged changes in the project changelog. The release drops support for Spark 3.4 and Flink 2.0, adds Flink 2.2 and 2.3, and includes Spark 4.2 in source releases. It expands engine support for version 3 capabilities such as Variant, geometry and geography, row lineage, deletion vectors, and encryption.

Older position-delete files that contain deleted row values remain readable, but writers and two maintenance operations reject them. The release also adds Hilbert-curve clustering and REST catalog features, including function endpoints and catalog-managed purge delegation. It includes groundwork for format version 4, which the guide says is not ready for production use. Operators are advised to inventory their engines and integrations, then test compatibility and maintenance behavior before upgrading.