Apache Iceberg v4 Roadmap: Adaptive Metadata Trees, Single-File Commits, and the Delta Convergence

This article provides a detailed analysis of the Apache Iceberg v4 roadmap, focusing on key architectural proposals such as adaptive metadata trees, single-file commits, relative table paths, column families, and an extensible statistics model. It explains how these proposals address metadata write amplification, metadata planning overhead, and format fragmentation in current Iceberg implementations. The article also discusses the potential convergence with Delta Lake 5.0 at the metadata level, practical guidance for teams evaluating v4, and unresolved community debates. It is highly relevant to IT/TECHNOLOGY as it covers data engineering, open-source table formats, and cloud-native data lakehouse architecture.