[HIVE-22578] CBO genOPTree is not failsafe for CTAS and VIEW statements

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0, 3.1.2
• Fix Version/s: 4.0.0-alpha-1
• Component/s: CBO
• Assignee: Aron Hamvas
• Reporter: Aron Hamvas
• Created: 04/Dec/19 10:04
• Updated: 27/Feb/24 22:23
• Resolved: 10/Dec/19 12:58

Description

If CBO fails during OT generation, it is supposed to skip CBO and fall back to SemanticAnalyzer generating the OT for the original AST. However, for CTAS and VIEW statements, the original AST is discarded and replaced with the new AST.
If OT generation for the new AST fails with a SemanticException, the compilation is destined to fail completely since we cannot fall back to the original and possibly valid AST.

Also, the SemanticException sometimes gets hidden and misjudged as a missing column statistics issue due to bad error handling.