[ARROW-554] [C++] Implement functions to conform unequal dictionaries amongst multiple Arrow arrays

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.12.0
• Component/s: C++
• Labels: Analytics pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/16191
• Assignee: Antoine Pitrou
• Reporter: Wes McKinney
• Created: 13/Feb/17 19:22
• Updated: 11/Jan/23 07:09
• Resolved: 19/Dec/18 18:54

Description

We may wish to either

• Conform the dictionary indices to reference a common dictionary
• Concatenate indices into a new array with a common dictionary

This is related to in-memory dictionary encoding, as you start with a partially-built dictionary and then add entries as you observe new ones in other dictionaries, all the while "rebasing" indices to consistently reference the same dictionary at the end

Issue Links

• links to: GitHub Pull Request #3165