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Xuefu Zhang commented on HIVE-13293: ------------------------------------ Hi [~lirui], Is checking num of partitions necessary because sampling job is triggered only if more than one partition? > Query occurs performance degradation after enabling parallel order by for > Hive on Spark > --------------------------------------------------------------------------------------- > > Key: HIVE-13293 > URL: https://issues.apache.org/jira/browse/HIVE-13293 > Project: Hive > Issue Type: Bug > Components: Spark > Affects Versions: 2.0.0 > Reporter: Lifeng Wang > Assignee: Rui Li > Attachments: HIVE-13293.1.patch, HIVE-13293.2.patch, > HIVE-13293.3.patch > > > I use TPCx-BB to do some performance test on Hive on Spark engine. And found > query 10 has performance degradation when enabling parallel order by. > It seems that sampling cost much time before running the real query. -- This message was sent by Atlassian JIRA (v6.3.4#6332)