[ARROW-13574] [C++] Add 'count all' option to count (hash) aggregate kernel

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 6.0.0
• Component/s: C++
• Labels: kernel pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/29221
• Assignee: David Li
• Reporter: David Li
• Created: 05/Aug/21 14:40
• Updated: 11/Jan/23 08:34
• Resolved: 11/Aug/21 17:14

Description

The current "count" hash aggregate kernel counts either all non-null or all null values, but doesn't count all values regardless of nullity (i.e. SQL "count(*)" or Pandas size()).

Issue Links

• is a child of: ARROW-13339 [C++] Implement hash_aggregate kernels (umbrella issue)
• links to: GitHub Pull Request #10895