Writing to an Apache Iceberg Table: How Commits and ACID Actually Work

This article is part 6 of a 15-part Apache Iceberg Masterclass. It details the exact six-step process for writing data to an Iceberg table: writing data files, creating manifest entries, creating/updating manifest files, creating a manifest list, creating a new metadata file, and performing an atomic commit. It explains how Iceberg provides ACID guarantees on object storage (like S3) via metadata-layer transactions, covers concurrent writes with optimistic concurrency control, and describes delete/update operations including Copy-on-Write and Merge-on-Read. The article is highly technical and relevant to data engineering, big data, and IT infrastructure.