[CALCITE-3764] AggregateCaseToFilterRule handles NULL values incorrectly

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.22.0
• Labels: pull-request-available
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 01/Feb/20 05:34
• Updated: 06/Mar/20 04:34
• Resolved: 04/Feb/20 00:17

Description

AggregateCaseToFilterRule handles NULL values incorrectly. It converts

SELECT COUNT(CASE WHEN b THEN NULL ELSE 1 END) FROM t

to

SELECT COUNT(*) FILTER (WHERE b IS FALSE) FROM t

which fails to count rows where b is UNKNOWN, so it should convert to

SELECT COUNT(*) FILTER (WHERE b IS NOT TRUE) FROM t

Issue Links

• links to: GitHub Pull Request #1781