[ARROW-16637] [C++] Add row-based utilities for encoding a batch and merging row tables

• Type: Sub-task
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/31988
• Assignee: Unassigned
• Reporter: Weston Pace
• Created: 23/May/22 22:29
• Updated: 11/Jan/23 11:45

Description

This PR adds a "row table" which is a high level API for a 2D structure that has row-major storage. It adds utilities to encode to & from the existing columnar structure via this high level API. Internally it uses RowTableImpl.

It also adds a merge utility that can merge two row tables together.

Issue Links

• links to: GitHub Pull Request #13220