[ARROW-15621] [C++] Add extension types to the YAML for different timestamp resolutions

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• Labels: substrait
• External issue URL: https://github.com/apache/arrow/issues/31080
• Assignee: Unassigned
• Reporter: Weston Pace
• Created: 09/Feb/22 03:39
• Updated: 11/Jan/23 11:38

Description

Substrait has decided that microsecond resolution timestamps are sufficient. Arrow has timestamps at a variety of resolutions.

If a user is fine casting to microsecond resolution then they don't actually need to do anything. However, if a user really wanted the source resolution (or maybe the semantics are slightly different around rounding) then we need to create extension types for these in the YAML.