[CASSANDRA-17762] LWT IF col = NULL is inconsistent with SQL NULL

• Type: Bug
• Status: Open
• Priority: Normal
• Resolution: Unresolved
• Fix Version/s: 5.x
• Component/s: CQL/Semantics
• Bug Category: Correctness
• Severity: Normal
• Complexity: Normal
• Discovered By: User Report
• Platform: All
• Assignee: Unassigned
• Reporter: Avi Kivity
• Created: 20/Jul/22 12:09
• Updated: 29/Aug/24 22:30

Description

In SQL, any comparison with NULL is NULL, which is interpreted as FALSE in a condition. To test for NULLness, you use IS NULL or IS NOT NULL.

But LWT uses IF col = NULL as a NULLness test. This is likely to confuse people coming from SQL and hamper attempts to extend the dialect.

Issue Links

• is related to: CASSANDRA-17719 CEP-15: Multi-Partition Transaction CQL Support (Alpha)
• relates to: CASSANDRA-10715 Allow filtering on NULL