[ARROW-13764] [C++] Implement ScalarAggregateOptions for count_distinct (grouped)

• 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/29392
• Assignee: David Li
• Reporter: Nicola Crane
• Created: 26/Aug/21 13:46
• Updated: 11/Jan/23 08:35
• Resolved: 30/Aug/21 17:15

Description

I'm writing the R bindings for the grouped count_distinct kernel, but the current implementation counts nulls as their own group. To match the R behaviour, I need to be able to specify whether or not to remove NA/NULL values.

Please could we have ScalarAggregateOptions implemented for count_distinct?

Issue Links

• blocks: ARROW-13618 [R] Use Arrow engine for summarize() by default
• relates to: ARROW-13620 [R] Binding for n_distinct()
• links to: GitHub Pull Request #11011