[IMPALA-12736] Backend changes for MERGE statement

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Implemented
• Component/s: Backend
• Labels: impala-iceberg
• Epic Color: ghx-label-13
• Assignee: Peter Rozsa
• Reporter: Peter Rozsa
• Created: 19/Jan/24 10:38
• Updated: 05/Sep/24 08:15
• Resolved: 05/Sep/24 08:15

Description

• Merge operator
  • duplicate check
  • matching WHEN MATCHED/WHEN NOT MATCHED clauses to the underlying rows
• Merge sink
  • based on UPDATE statement
  • dispatching 3 cases:
    • delete-write
    • delete
    • write