[ARROW-9697] [C++][Dataset] num_rows method for Dataset/Scanner

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 5.0.0
• Component/s: C++
• Labels: dataset pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/25753
• Assignee: David Li
• Reporter: Neal Richardson
• Created: 11/Aug/20 21:21
• Updated: 11/Jan/23 08:08
• Resolved: 05/May/21 20:58

Description

Something like Scanner::ToTable except first Project to keep 0 columns, and for each record batch, grab the num_rows. Then sum the resulting vector.

Issue Links

• is related to: ARROW-12598 [C++][Dataset] Implement row-count for CSV or allow selecting 0 columns from CSV
• links to: GitHub Pull Request #10060