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Ferdinand Xu commented on HIVE-15682: ------------------------------------- Hi [~xuefuz] {noformat} select count(*) from (select request_lat from dwh.fact_trip where datestr > '2017-01-27' order by request_lat) x; Origin: 246.56, 342.78, 216.40, 216.587, 270.805, 449.232, 233.406 AVG: 282.25 patch: 125.21, 123.22, 166.31, 168.30, 120.428, 119.21, 120.385 AVG: 134.72 {noformat} What kind of data scales do you use to evaluate the performance? We can evaluate this patch using TPC-DS and TPCx-BB. > Eliminate per-row based dummy iterator creation > ----------------------------------------------- > > Key: HIVE-15682 > URL: https://issues.apache.org/jira/browse/HIVE-15682 > Project: Hive > Issue Type: Improvement > Components: Spark > Affects Versions: 2.2.0 > Reporter: Xuefu Zhang > Assignee: Xuefu Zhang > Fix For: 2.2.0 > > Attachments: HIVE-15682.patch > > > HIVE-15580 introduced a dummy iterator per input row which can be eliminated. > This is because {{SparkReduceRecordHandler}} is able to handle single key > value pairs. We can refactor this part of code 1. to remove the need for a > iterator and 2. to optimize the code path for per (key, value) based (instead > of (key, value iterator)) processing. It would be also great if we can > measure the performance after the optimizations and compare to performance > prior to HIVE-15580. -- This message was sent by Atlassian JIRA (v6.3.15#6346)