[ARROW-9699] [C++][Compute] Improve mode kernel performance for small integer types

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 2.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/25755
• Assignee: Yibo Cai
• Reporter: Yibo Cai
• Created: 12/Aug/20 04:26
• Updated: 11/Jan/23 08:08
• Resolved: 25/Aug/20 12:06

Description

Mode kernel usesl hash table to count distinct values. For small integer types (bool, int8, uint8), counting directly with a value indexed array can be more efficient. This card is to evaluate the approach and upstream patch if workable.

Issue Links

• links to: GitHub Pull Request #7963