[HIVE-25269] When the skew and parallel parameters are true simultaneously, the result is less data

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.1.0, 3.1.2
• Component/s: Physical Optimizer, SQL
• Assignee: Unassigned
• Reporter: GuangMing Lu
• Created: 19/Jun/21 15:29
• Updated: 21/Jun/21 15:44

Description

When the params of hive.optimize.skewjoin, hive.groupby.skewindata and hive.exec.parallel are true, and exec sql such as 'INSERT... FROM (SUBQUERY UNIONALL ...GROUP BY...) A JOIN/LEFT JOIN A.expression', result data will be reduced. Details of SQL and test data can be found in the attachment