[ARROW-17556] [C++] Unbound scan projection expression leads to all fields being loaded

• Type: Bug
• Status: Resolved
• Priority: Blocker
• Resolution: Fixed
• Fix Version/s: 10.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/32808
• Assignee: Vibhatha Lakmal Abeykoon
• Reporter: Weston Pace
• Created: 29/Aug/22 20:06
• Updated: 11/Jan/23 11:51
• Resolved: 14/Oct/22 18:19

Description

If a projection expression is unbound then we should bind it to the (augmented) dataset schema and carry on. Instead it appears we are interpreting "unbound expression" as "nothing set at all" and loading all fields.

Issue Links

• fixes: ARROW-17559 [R][C++] Regression: big performance hit after removing schema binding
• links to: GitHub Pull Request #14264