[DRILL-2181] Throw proper error message when flatten is used within an 'order by' or 'group by'

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.0.0
• Component/s: Query Planning & Optimization
• Assignee: Sean Hsuan-Yi Chu
• Reporter: Rahul Kumar Challapalli
• Created: 09/Feb/15 02:26
• Updated: 06/May/15 00:27
• Resolved: 29/Apr/15 23:56

Description

git.commit.id.abbrev=c54bd6a

Flatten can be used within a group by or order by statement when the output of flatten is a scalar. However drill currently does not support using flatten with the above operators when its output is not a scalar. In such cases we should show a more appropriate error, possibly indicating how to correct the query as well

Currently this is what we get. This is obscure and does not pinpoint the issue

select * from `data1.json` order by flatten(events);
Query failed: RemoteRpcException: Failure while running fragment., org.apache.drill.exec.vector.NullableIntVector cannot be cast to org.apache.drill.exec.vector.RepeatedVector [ c3d85d23-7ea0-43ea-bbd3-ac18a0aa2de3 on qa-node191.qa.lab:31010 ]
[ c3d85d23-7ea0-43ea-bbd3-ac18a0aa2de3 on qa-node191.qa.lab:31010 ]


Error: exception while executing query: Failure while executing query. (state=,code=0)

Issue Links

• is related to: DRILL-2228 Projecting '*' returns all nulls when we have flatten in a filter and order by
• is related to: DRILL-2232 Flatten functionality not well defined when we use flatten in an order by without projecting it
• is related to: DRILL-2264 Incorrect data when we use aggregate functions with flatten