[IMPALA-12881] Use JoinNode.getFkPkJoinCardinality in reduceCardinalityForScanNode

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: Impala 4.4.0
• Component/s: Frontend
• Target Version: Impala 4.4.0
• Epic Color: ghx-label-3
• Assignee: Riza Suminto
• Reporter: Riza Suminto
• Created: 08/Mar/24 00:18
• Updated: 04/Apr/24 21:11
• Resolved: 04/Apr/24 21:11

Description

IMPALA-12018 adds reduceCardinalityForScanNode to lower cardinality estimation when runtime filter is involved. It calls 
JoinNode.computeGenericJoinCardinality(). However, if the originating join node has FK-PK conjunct, it should be possible to obtain lower cardinality estimate by calling JoinNode.getFkPkJoinCardinality() instead.