[HIVE-9636] Apply IdentityProjectRemover after other optimizations

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Invalid
• Assignee: Jesús Camacho Rodríguez
• Reporter: Jesús Camacho Rodríguez
• Created: 10/Feb/15 11:51
• Updated: 27/Feb/24 22:13
• Resolved: 28/May/18 17:04

Description

IdentityProjectRemove optimizer may remove some Project operators that change the table alias for the input columns; this might cause optimizations such as StatsOptimizer, that rely on colExprMap and consequently store table aliases, to behave incorrectly.
To avoid this, we could apply IdentityProjectRemove optimization after all the rest have been previously applied, and document it accordingly.