[HIVE-16050] Regression: Union of null with non-null

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.2.0
• Fix Version/s: 2.2.0
• Component/s: Query Planning
• Release Note: Regression: Union of null with non-null (Gopal V, reviewed by Sergey Shelukhin)
• Assignee: Gopal Vijayaraghavan
• Reporter: Gopal Vijayaraghavan
• Created: 27/Feb/17 19:17
• Updated: 25/Jul/17 20:05
• Resolved: 01/Mar/17 12:29

Description

hive> select null as c1 union select 1 as c2;
    FAILED: SemanticException Schema of both sides of union should match: Column c1 is of type void on first table and type int on second table. Cannot tell the position of null AST.

This looks related to HIVE-14251 which removed certain cases from the UNION type coercion operations.