abstractdog commented on PR #6793: URL: https://github.com/apache/hive/pull/6793#issuecomment-5926538252
latest testing results: ## TPC-DS A/B: `hive.llap.io.parquet.native.enabled` 99 queries × 3 reps × 2 arms = **594 runs, 0 failures**, against `tpcds_partitioned_parquet_10`. Metric is `Run DAG` from the Tez query summary (pure DAG execution, excluding compile/submit/fetch). Cluster restarted before each arm. **A/B validity:** `false` arm showed LLAP IO counters in 0/297 runs, `true` arm in 297/297 — the flag really does switch the read path, so the comparison is valid. ### Correctness: no differences | | queries | |---|---| | byte-identical output | 90 | | identical, both empty | 6 | | identical multiset, row order differs | 3 (q31, q65, q71) | | **value or row-count differenc The 3 ordering differences are read-path defects: for those queries the row order also varies between repetitions with the flag held constant, in both arms (`ORDER BY` on constant/tietie-breaker). q77 is a fourth such query, which happened to order stably in the `false` arm. ### Performance: 9.1% faster warm, 19.5% faster on first execution | | `false` | `true` | change | |---|---:|---:|---:| | total `Run DAG`, warm | 995.8s | total `Run DAG`, first execution | 1605.4s | 1291.7s | **−19.5%** | Median per-query change **−7.9%**; 84/99 queries faster by some margin. 32 robustly faster (every warm sample beats every ` noise, 7 material but indeterminate. The win is broad rather than a few outliers — the top 8 queries account for only 46% of the total saving. <details> <summary>Caveats</summary> Single-box run, 10 GB scale factor. Run-to-run spread exceeds 15% between a query's own two warm reps for 25 (query, arm) pairs, so the aggregate and the robust counts are the load-bearing numbers — an individual query's percentage is indicative only. </details> -- 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]
