[SPARK-30207] Enhance the SQL NULL Semantics document

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0
• Fix Version/s: 3.0.0
• Component/s: Documentation, SQL
• Assignee: Yuanjian Li
• Reporter: Yuanjian Li
• Created: 10/Dec/19 17:31
• Updated: 11/Dec/19 18:05
• Resolved: 11/Dec/19 13:03

Description

Enhancement of the SQL NULL Semantics document: sql-ref-null-semantics.html.

Clarify the behavior of `UNKNOW` for both `EXIST` and `IN` operation.

Issue Links

• links to: GitHub Pull Request #26837