[DRILL-4975] Null equality join over non existing columns returns nulls forever

• Type: Bug
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 1.9.0
• Component/s: Execution - Flow
• Assignee: Unassigned
• Reporter: Khurram Faraaz
• Created: 27/Oct/16 19:33
• Updated: 27/Oct/16 19:33

Description

Null equality join query that involves non-existing columns in the join predicate, runs for ever and returns nulls.
Since the columns are not part of the parquet file, the join should fail gracefully, and not return infinite number of nulls.

SELECT t1.col_blah , t2.col_blah FROM typeall_l t1, typeall_r t2 WHERE t1.col_blah = t2.col_blah OR ( t1.col_blah IS NULL AND t2.col_blah IS NULL );
...
| null     | null      |
| null     | null      |
| null     | null      |
| null     | null      |
| null     | null      |
| null     | null      |
...

Upon removing, OR ( t1.col_blah IS NULL AND t2.col_blah IS NULL ) from the query, no results are returned, as expected.