[PIG-846] MultiQuery optimization in some cases has an issue when there is a split in the map plan

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.3.0
• Fix Version/s: 0.3.0
• Hadoop Flags: Reviewed
• Assignee: Pradeep Kamath
• Reporter: Pradeep Kamath
• Created: 12/Jun/09 20:53
• Updated: 24/Mar/10 22:11
• Resolved: 13/Jun/09 05:29

Description

The following script produces the error that follows:

A = LOAD 'input.txt' as (f0, f1, f2, f3, f4, f5, f6, f7, f8); 
B = FOREACH A GENERATE f0, f1, f2, f3, f4;
B1 = foreach B generate f0, f1, f2;
C = GROUP B1 BY (f1, f2);
STORE C into 'foo1';

B2 = FOREACH B GENERATE f0, f3, f4;
E = GROUP B2 BY (f3, f4);
STORE E into 'foo2';

F = FOREACH A GENERATE f0, f5, f6, f7, f8;
F1 = FOREACH F GENERATE f0, f5,f6;
G = GROUP F1 BY (f5, f6);
STORE G into 'foo3';

F2  = FOREACH F GENERATE f0, f7, f8;
I = GROUP F2 BY (f7, f8);
STORE I into 'foo4';

Exception encountered during execution:

java.lang.NullPointerException
	at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPackage.getValueTuple(POPackage.java:262)
	at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POPackage.getNext(POPackage.java:209)
	at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POMultiQueryPackage.getNext(POMultiQueryPackage.java:186)
	at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POMultiQueryPackage.getNext(POMultiQueryPackage.java:186)
	at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce$Reduce.processOnePackageOutput(PigMapReduce.java:277)
	at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce$Reduce.reduce(PigMapReduce.java:268)
	at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigMapReduce$Reduce.reduce(PigMapReduce.java:142)
	at org.apache.hadoop.mapred.ReduceTask.run(ReduceTask.java:318)
	at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:2207)