yihua opened a new pull request, #20171: URL: https://github.com/apache/hudi/pull/20171
### Describe the issue this Pull Request addresses issue: #20168 Under the pluggable table format (RFC-93) only copy-on-write commits become visible to Iceberg readers. A merge-on-read deltacommit writes log files that have no Iceberg representation, compaction and merge-on-read rollback complete without notifying the table format, and XTable's age-based snapshot expiry conflicts with the plugin's timeline fencing. ### Summary and Changelog Adds RFC-114, which proposes a merge-on-read write mode where an update becomes a positional delete against the record's current file group plus an insert into a new file slice, so every deltacommit maps to one Iceberg V3 snapshot of data files plus deletion vectors. It also covers the table format hooks on compaction and rollback, retention alignment at archival, and the Iceberg-side changes in Apache XTable on top of apache/incubator-xtable#894. The design keeps the key points in the body and pushes proof-of-concept findings, index interplay and the XTable upstreaming order into appendices. The writer changes come in a companion PR; the Iceberg side has a working end-to-end proof of concept on Iceberg 1.11. ### Impact Documentation only. ### Risk Level none ### Documentation Update none ### Contributor's checklist - [x] Read through [contributor's guide](https://hudi.apache.org/contribute/how-to-contribute) - [x] Enough context is provided in the sections above - [ ] Adequate tests were added if applicable -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
