[TAJO-238] NullPointerException occurs when a query includes an alias of UDF at the group by clause

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Not A Problem
• Fix Version/s: 0.2-incubating
• Component/s: Function/UDF
• Assignee: Jihoon Son
• Reporter: Jihoon Son
• Created: 08/Oct/13 12:56
• Updated: 09/Oct/13 09:26
• Resolved: 09/Oct/13 03:43

Description

The query which I run is

SELECT hour(time) as t, sum(size) 
FROM log 
GROUP BY t  
ORDER BY t asc

The function hour() returns the hour of values of the column 'time'.
The error log is

13/10/08 21:21:18 ERROR worker.Task: java.lang.NullPointerException
        at org.apache.tajo.catalog.Schema.getColumnId(Schema.java:154)
        at org.apache.tajo.engine.eval.FieldEval.eval(FieldEval.java:51)
        at org.apache.tajo.engine.eval.GeneralFunctionEval.terminate(GeneralFunctionEval.java:62)
        at org.apache.tajo.engine.planner.physical.HashAggregateExec.next(HashAggregateExec.java:94)
        at org.apache.tajo.engine.planner.physical.MemSortExec.next(MemSortExec.java:54)
        at org.apache.tajo.engine.planner.physical.IndexedStoreExec.next(IndexedStoreExec.java:92)
        at org.apache.tajo.worker.Task.run(Task.java:381)
        at org.apache.tajo.worker.TaskRunner$2.run(TaskRunner.java:364)
        at java.lang.Thread.run(Thread.java:679)