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Dapeng Sun edited comment on HIVE-15682 at 2/13/17 9:03 AM: ------------------------------------------------------------ Hi Xuefu, sorry, I didn't receive the email notification of this JIRA. Do you mean you want to test {{order by}} likes {{`select count(*) from (select request_lat from dwh.fact_trip where datestr > '2017-01-27' order by request_lat) x;`}} about {{w/ HIVE-15580}}, {{w/o HIVE-15580}} at my environment? was (Author: dapengsun): Hi Xuefu, sorry, I didn't receive the email notification of this JIRA. Do you mean you want to test {{order by}} likes {{`select count(*) from (select request_lat from dwh.fact_trip where datestr > '2017-01-27' order by request_lat) x;`}} about {{ w/ HIVE-15580 }}, {{ w/o HIVE-15580 }} at my environment? > 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)