[TAJO-866] COUNT DISTINCT with other aggregation function throws ClassCastException.

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Fix Version/s: 0.9.0
• Assignee: Hyoungjun Kim
• Reporter: Hyoungjun Kim
• Created: 05/Jun/14 12:35
• Updated: 25/Jun/14 08:14
• Resolved: 25/Jun/14 07:58

Description

I tested with the following data and query.

default> select * from table1;
id,code,qty
-------------------------------
1,a,3
1,a,4
1,b,5
2,a,1
2,c,2
2,d,3

default> select id, count(distinct code), avg(qty) from table101 group by id;
2014-06-05 21:29:56,960 ERROR: org.apache.tajo.worker.Task (run(390)) - org.apache.tajo.datum.NullDatum cannot be cast to org.apache.tajo.datum.ProtobufDatum
java.lang.ClassCastException: org.apache.tajo.datum.NullDatum cannot be cast to org.apache.tajo.datum.ProtobufDatum
	at org.apache.tajo.engine.function.builtin.AvgLong.merge(AvgLong.java:66)
	at org.apache.tajo.engine.eval.AggregationFunctionCallEval.merge(AggregationFunctionCallEval.java:59)
	at org.apache.tajo.engine.planner.physical.SortAggregateExec.next(SortAggregateExec.java:77)
	at org.apache.tajo.engine.planner.physical.DistinctGroupbySortAggregationExec.next(DistinctGroupbySortAggregationExec.java:88)
	at org.apache.tajo.engine.planner.physical.StoreTableExec.next(StoreTableExec.java:77)
	at org.apache.tajo.worker.Task.run(Task.java:382)
	at org.apache.tajo.worker.TaskRunner$1.run(TaskRunner.java:406)
	at java.lang.Thread.run(Thread.java:744)