[ARROW-6736] [Rust] [DataFusion] Aggregate expressions get evaluated repeatedly

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.15.0
• Fix Version/s: 0.16.0
• Component/s: Rust, Rust - DataFusion
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/23077
• Assignee: Andy Grove
• Reporter: Andy Grove
• Created: 30/Sep/19 00:07
• Updated: 11/Jan/23 07:49
• Resolved: 04/Oct/19 00:10

Description

There is a design flaw in the new aggregate expression traits and implementations where the input to the aggregate expression gets evaluated against the whole batch once for each row in the batch. For example, if the batch has 1024 rows then the expression gets evaluated 1024 times instead of once.

Issue Links

• links to: GitHub Pull Request #5542