[HIVE-15839] Don't force cardinality check if only WHEN NOT MATCHED is specified

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.2.0
• Component/s: Query Planning, Query Processor, Transactions
• Target Version/s: 2.2.0
• Assignee: Eugene Koifman
• Reporter: Eugene Koifman
• Created: 07/Feb/17 19:50
• Updated: 25/Jul/17 20:05
• Resolved: 13/Feb/17 22:46

Description

should've been part of HIVE-14949

if only WHEN NOT MATCHED is specified then the join is basically an anti-join and we are not retrieving any values from target side. So the cardinality check is just overhead (though presumably very minor since the filter above the join will filter everything and thus there is nothing to group)

Issue Links

• is blocked by: HIVE-15871 Cannot insert into target table because column number/types are different with hive.merge.cardinality.check=false
• relates to: HIVE-14949 Add Cardinality Violation check in SQL MERGE stmt