[HIVE-11409] CBO: Calcite Operator To Hive Operator (Calcite Return Path): add SEL before UNION

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.3.0, 2.0.0
• Component/s: CBO
• Assignee: Pengcheng Xiong
• Reporter: Pengcheng Xiong
• Created: 30/Jul/15 05:55
• Updated: 27/Feb/24 22:23
• Resolved: 05/Aug/15 20:56

Description

Two purpose: (1) to ensure that the data type of non-primary branch (the 1st branch is the primary branch) of union can be casted to that of the primary branch; (2) to make UnionProcessor optimizer work; (3) if the SEL is redundant, it will be removed by IdentidyProjectRemover optimizer.