[HIVE-1] [hive] redundant expression evaluation in group by stage 1

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Query Processor
• Assignee: Carter Shanklin
• Reporter: Namit Jain
• Created: 11/Sep/08 01:34
• Updated: 05/Sep/24 18:03

Description

We can be smarter in terms of this list of what parameters we evaluate in the first stage, we should only evaluate those that are common across the group by clauses.

All expressions and aggregation function parameters are evaluated in the first stage thereby increasing data flow. It might be better to only evaluate common expressions