deniskuzZ opened a new pull request, #6925: URL: https://github.com/apache/hive/pull/6925
### What changes were proposed in this pull request? - Merge-on-read deleted records carry only PARTITION__SPEC__ID, PARTITION__KEY, FILE__PATH, ROW__POSITION; readers fill PARTITION__KEY once per file with a compact encoding of the partition - Ordinary deletes and the merge task share one record layout; the delete writer decodes each distinct partition once - Statistics size PARTITION__KEY by a fixed 8-byte average length, the width PARTITION__HASH had - Deletes from files of a spec whose partition source column was dropped fail with a clear message instead of "Cannot build accessor" - Stacked on HIVE-30112 ### Why are the changes needed? Optimization: the partition encoding per deleted record drops from 1.5-3.4 KB to 0-17 B, and the shuffle from all table columns to 4 virtual columns ### Does this PR introduce _any_ user-facing change? Yes: the PARTITION__HASH virtual column is removed; a MERGE checks cardinality on FILE__PATH, ROW__POSITION ### How was this patch tested? - TestIcebergAcidUtil, TestHiveIcebergDeleteWriter, TestHiveIcebergDeletionVectors, TestHiveIcebergCRUD, TestStatsUtils - iceberg_dml_deleted_record_columns.q, iceberg_merge_delete_files.q, query_iceberg_virtualcol.q; regenerated plan goldens -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
