thomasrebele commented on PR #6163: URL: https://github.com/apache/hive/pull/6163#issuecomment-3492582155
I've investigated the changes to the q.out file for `ql/src/test/queries/clientpositive/perf/query96.q`. The NUM_DISTINCT varies slightly between the old and the new metastore dump (due to the randomness of the HLL algorithm). That influences the selectivity of certain predicates, which lead to different row count estimations. Sometimes they change enough to influence the join order. The new metastore is an improvement. Besides the histogram statistics, it fixes the statistics for NUM_NULLS, which are very often 0 in the old dump. -- 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]
