[HIVE-7518] Output vectorized GROUP BY aggregate fields from STRUCTs for AVG, etc as columns so downstream reduce can be vectorized

• Type: Sub-task
• Status: Resolved
• Priority: Major
• Resolution: Incomplete
• Assignee: Matt McCline
• Reporter: Matt McCline
• Created: 25/Jul/14 22:33
• Updated: 22/Jul/18 08:27
• Resolved: 22/Jul/18 08:27

Description

Today, aggregates like AVG are output from VectorGroupByOperator as a STRUCT. This prevents downstream operators in map, reduce shuffle, and reduce from being vectorized.

Take the STRUCT fields used for AVG (for example) and output them (vector) columns.

NOTE: downstream VectorGroupByOperator needs to accept column form…
• That is, (reduce) merge of partial aggregates is different than map.