[HIVE-21768] JDBC: Strip the default union prefix for un-enclosed UNION queries

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.1.1, 4.0.0
• Fix Version/s: 4.0.0-alpha-1
• Component/s: Logical Optimizer
• Assignee: Gopal Vijayaraghavan
• Reporter: Gopal Vijayaraghavan
• Created: 21/May/19 22:51
• Updated: 27/Feb/24 22:23
• Resolved: 28/May/19 22:08

Description

beeline> select 1  union all select 2;

+----------+
| _u1._c0  |
+----------+
| 2        |
| 1        |
+----------+

The _u1 is superfluous and harmful to result schema parsing.