iceberg-v4

1. November 9, 202620 min read

   Iceberg v4's _last_updated_time Column: "Rows Changed Since T" Without Rewriting Manifests

   Iceberg v4's _last_updated_time column records when each row last changed, inherited from the snapshot timestamp with no manifest rewrite.

2. November 9, 202620 min read

   Should Iceberg v4 Stop Writing ORC and Avro Data Files? The Feature-Gap Case and the Read Path That Stays

   Iceberg v4 may stop writing ORC and Avro data files while keeping existing files readable, plus how to audit an estate and plan a migration.

3. November 9, 202620 min read

   Iceberg v4 Stats-Only Fields: How Tables Store Statistics for Partition Expressions, and Why tight_stats Replaced tight_bounds

   Iceberg v4 stats-only fields give derived values a field ID in content_stats, and the file-level tight_stats flag says when statistics are exact.

4. October 28, 202633 min read

   Primary Keys Come to Apache Iceberg V4, and Most of Them Start Out Unenforced

   Apache Iceberg V4 adds primary key, unique and check constraints, an enforced flag and per-snapshot status. What the spec says and how to prepare tables.

5. September 21, 202632 min read

   What Iceberg v4's Proposed FILE Type Means for Multimodal Tables

   Iceberg v4's proposed FILE type brings first-class media references to tables, via Parquet's FILE logical type, ranges, checksums, and pre-signed URLs.

6. August 25, 202631 min read

   Parquet-Only Manifests in Iceberg v4: Why the Metadata Layer Is Going Columnar

   Iceberg v4 is moving manifests from Avro to Parquet so planners can read only the stats they need. Why the metadata layer is going columnar.

7. August 24, 202631 min read

   Iceberg v4's Adaptive Metadata Tree, Explained From First Principles

   Iceberg v4's adaptive metadata tree, explained from first principles: why commits rewrite too much today and how the tree makes change cheaper.

8. August 24, 202630 min read

   Why Iceberg v4 Is Really About Making the Cost of Change Proportional to the Change

   Iceberg v4 is really about making the cost of a change proportional to the change. The principle, the current tax, and what the redesign pays down.

9. August 4, 202621 min read

   Reading the Apache Iceberg V4 Proposals Before They Land

   A field guide to the Apache Iceberg V4 proposals: adaptive metadata trees, single-file commits, typed statistics, column families, and what is safe.

10. July 6, 202630 min read

    The State of Apache Iceberg v4 in July 2026: What the Dev List Tells Us About the Format's Next Chapter

    What the Iceberg v4 dev list tells us about adaptive metadata trees, single-file commits, column updates, and the format's next chapter in mid-2026.

11. June 22, 202613 min read

    Iceberg v4 Performance: Root Manifests and Calls

    Apache Iceberg v4 discussion should focus on planning cost, metadata layout, and object storage round trips, not vague claims about faster tables.

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