[ARROW-10683] [Rust] Remove Array.data method in favor of .data_ref to make performance impact of clone more obvious

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Component/s: Rust
• External issue URL: https://github.com/apache/arrow/issues/26634
• Assignee: Unassigned
• Reporter: Jörn Horstmann
• Created: 21/Nov/20 22:32
• Updated: 11/Jan/23 08:14

Description

The `Array.data()` method is a real performance foot-gun since it involves cloning an `Arc` which is not obvious to users. When used in innner loops that can cause big performance impacts. The cloning itself might not be a problem, but I think it sometimes prohibits other compiler optimizations.

It would be better to remove this method and let users call `array_ref()` and only clone when really needed.

Most of the current usages seem to be in test assertions which should be easy to refactor.