Details
-
Improvement
-
Status: Open
-
Critical
-
Resolution: Unresolved
-
1.2.0
-
None
Description
When the input on LHS of UNION operator is empty and there is non empty input on RHS of Union, we need to return the data from the RHS. Currently we return SchemaChangeException.
0: jdbc:drill:schema=dfs.tmp> select key1 from `empty.json` UNION select key1 from `fewRows.json`; Error: SYSTEM ERROR: SchemaChangeException: The left input of Union-All should not come from an empty data source Fragment 0:0 [Error Id: f0fcff87-f470-46a8-9733-316b7da1a87f on centos-02.qa.lab:31010] (state=,code=0)
Attachments
Issue Links
- is related to
-
DRILL-3659 UnionAllRecordBatch infers wrongly from next() IterOutcome values
- Resolved
- relates to
-
DRILL-2288 ScanBatch violates IterOutcome protocol for zero-row sources [was: missing JDBC metadata (schema) for 0-row results...]
- Closed
Seems likely to be related to
DRILL-2288andDRILL-3659.