[ARROW-11797] [C++][Dataset] Provide Scanner methods to yield/visit scanned batches

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 4.0.0
• Component/s: C++
• Labels: dataset pull-request-available
• Assignee: Ben Kietzman
• Reporter: Ben Kietzman
• Created: 26/Feb/21 17:48
• Updated: 15/Apr/21 13:26
• Resolved: 15/Apr/21 01:09

Description

From discussion in https://issues.apache.org/jira/browse/ARROW-11782

It'd be useful to consumers of Scanner to receive an iterator of scanned record batches or apply a visitor to batches as they are scanned without handling ScanTasks. For example, this could enable aggregations or other computations which don't require the entire table to be materialized.

Issue Links

• is related to: ARROW-12369 [C++][Dataset] Scanner::TakeRows should push down the query if possible
• is related to: ARROW-11782 [GLib][Ruby][Dataset] Remove bindings for internal classes
• links to: GitHub Pull Request #9589