[ARROW-5354] [C++] allow Array to have null buffers when all elements are null

• Type: New Feature
• Status: Closed
• Priority: Minor
• Resolution: Won't Fix
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/21813
• Assignee: Ben Kietzman
• Reporter: Ben Kietzman
• Created: 16/May/19 18:47
• Updated: 11/Jan/23 07:39
• Resolved: 18/Sep/19 11:07

Description

In the case of all elements of an array being null, no buffers whatsoever need to be allocated (similar to NullArray). This is a more extreme case of the optimization which allows the null bitmap buffer to be null if all elements are valid. Currently arrow::Array requires at least a null bitmap buffer to be allocated (and all bits set to 0).

Issue Links

• links to: GitHub Pull Request #4329