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ASF GitHub Bot logged work on HIVE-25335: ----------------------------------------- Author: ASF GitHub Bot Created on: 14/May/22 00:25 Start Date: 14/May/22 00:25 Worklog Time Spent: 10m Work Description: zhengchenyu opened a new pull request, #3292: URL: https://github.com/apache/hive/pull/3292 I found an application which is slow in our cluster, because the proccess bytes of one reduce is very huge, but only two reduce. when I debug, I found the reason. Because in this sql, one big size table (about 30G) with few row count(about 3.5M), another small size table (about 100M) have more row count (about 3.6M). So JoinStatsRule.process only use 100M to estimate reducer's number. But we need to process 30G byte in fact. https://issues.apache.org/jira/browse/HIVE-25335 Issue Time Tracking ------------------- Worklog Id: (was: 770442) Time Spent: 2h 40m (was: 2.5h) > Unreasonable setting reduce number, when join big size table(but small row > count) and small size table > ------------------------------------------------------------------------------------------------------ > > Key: HIVE-25335 > URL: https://issues.apache.org/jira/browse/HIVE-25335 > Project: Hive > Issue Type: Improvement > Reporter: zhengchenyu > Assignee: zhengchenyu > Priority: Major > Labels: pull-request-available > Attachments: HIVE-25335.001.patch > > Time Spent: 2h 40m > Remaining Estimate: 0h > > I found an application which is slow in our cluster, because the proccess > bytes of one reduce is very huge, but only two reduce. > when I debug, I found the reason. Because in this sql, one big size table > (about 30G) with few row count(about 3.5M), another small size table (about > 100M) have more row count (about 3.6M). So JoinStatsRule.process only use > 100M to estimate reducer's number. But we need to process 30G byte in fact. -- This message was sent by Atlassian Jira (v8.20.7#820007)