[PIG-2493] UNION causes casting issues

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.9.1, 0.10.0
• Fix Version/s: 0.9.3, 0.11, 0.10.1
• Hadoop Flags: Reviewed
• Assignee: Vivek Padmanabhan
• Reporter: Anitha Raju
• Created: 27/Jan/12 04:44
• Updated: 06/Jan/13 23:57
• Resolved: 18/Dec/12 21:33

Description

Hi,

For the below script,

A = load '/user/anithar/ip' as (a);
B = load '/user/anithar/ip1' as (a);
C = union  A , B ;
D = foreach C generate (chararray)a;
dump D;

it gives casting error at runtime

org.apache.pig.backend.executionengine.ExecException: ERROR 1075: Received a bytearray from the UDF. Cannot determine how to convert the bytearray to string.
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POCast.getNext(POCast.java:660)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.getNext(PhysicalOperator.java:322)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:332)
        at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:284)
        at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.runPipeline(PigGenericMapBase.java:267)
        at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:262)
        at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigGenericMapBase.map(PigGenericMapBase.java:64)
        at org.apache.hadoop.mapreduce.Mapper.run(Mapper.java:144)
        at org.apache.hadoop.mapred.MapTask.runNewMapper(MapTask.java:764)
        at org.apache.hadoop.mapred.MapTask.run(MapTask.java:370)
        at org.apache.hadoop.mapred.Child$4.run(Child.java:255)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.Subject.doAs(Subject.java:396)
        at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInformation.java:1082)
        at org.apache.hadoop.mapred.Child.main(Child.java:249)

It looks like in POCast.java the value of "funcSpec" is not getting any value(stays null when there is a UNION involved), causing "caster" to get null and thus the exception.

The same works in 0.8 without any issue.

Regards,
Anitha