[CALCITE-4350] The reverse operation of collation direction is overly relaxed

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.27.0
• Component/s: core
• Labels: pull-request-available
• Assignee: Liya Fan
• Reporter: Liya Fan
• Created: 23/Oct/20 05:59
• Updated: 03/Jun/21 22:31
• Resolved: 03/Nov/20 02:31

Description

For the current implementation, RelFieldCollation#Direction#reverse returns DESCENDING for STRICTLY_ASCENDING, and returns ASCENDING for STRICTLY_DESCENDING.

This is overly relaxed. In a strict manner, it should return STRICTLY_DESCENDING for STRICTLY_ASCENDING, and vice versa. 

If the user needs to get the relaxed reverse direction, they may call collation.getDirection().reverse().lax();, as in many places of our code base. 

Do you agree?

Issue Links

• links to: GitHub Pull Request #2231