Major Description
Multi-query optimization fails to merge 2 branches when 1 is a result of Group By ALL and another is a result of Group By field1 where field 1 is of type long. Here is the script that fails with multi-query on.
data = LOAD 'test' USING PigStorage('\t') AS (a:long, b:double, c:double);
A = GROUP data ALL;
B = FOREACH A GENERATE SUM(data.b) AS sum1, SUM(data.c) AS sum2;
C = FOREACH B GENERATE (sum1/sum2) AS rate;
STORE C INTO 'result1';
D = GROUP data BY a;
E = FOREACH D GENERATE group AS a, SUM(data.b), SUM(data.c);
STORE E into 'result2';
Here is the exception from the logs
java.lang.ClassCastException: org.apache.pig.data.DefaultTuple cannot be cast to org.apache.pig.data.DataBag
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject.processInputBag(POProject.java:399)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POProject.getNext(POProject.java:180)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.processInput(POUserFunc.java:145)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:197)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POUserFunc.getNext(POUserFunc.java:235)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.processPlan(POForEach.java:254)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POForEach.getNext(POForEach.java:204)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.PhysicalOperator.processInput(PhysicalOperator.java:231)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.POLocalRearrange.getNext(POLocalRearrange.java:240)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.PODemux.runPipeline(PODemux.java:264)
at org.apache.pig.backend.hadoop.executionengine.physicalLayer.relationalOperators.PODemux.getNext(PODemux.java:254)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.processOnePackageOutput(PigCombiner.java:196)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:174)
at org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.PigCombiner$Combine.reduce(PigCombiner.java:63)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.combineAndSpill(MapTask.java:906)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.sortAndSpill(MapTask.java:786)
at org.apache.hadoop.mapred.MapTask$MapOutputBuffer.flush(MapTask.java:698)
at org.apache.hadoop.mapred.MapTask.run(MapTask.java:228)
at org.apache.hadoop.mapred.TaskTracker$Child.main(TaskTracker.java:2206)