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Pradeep Kamath commented on PIG-935: ------------------------------------ Review Comment: The fix looks good - the only change that would be good to have is in MRCompiler.getSamplingJob() to explicity check if any field position obtained from the getSortCols() method is -1 and in those cases throw an "Internal Error setting up sampling job" exception (you may need to introduce a new error code and follow the error handling guidelines to do this. > Skewed join throws an exception when used with map keys > ------------------------------------------------------- > > Key: PIG-935 > URL: https://issues.apache.org/jira/browse/PIG-935 > Project: Pig > Issue Type: Bug > Reporter: Sriranjan Manjunath > Attachments: skjoinmapbug.patch > > > Skewed join throws a runtime exception for the following query: > A = load 'map.txt' as (e); > B = load 'map.txt' as (f); > C = join A by (chararray)e#'a', B by (chararray)f#'a' using "skewed"; > explain C; > Exception: > Caused by: java.lang.ClassCastException: > org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.POCast > cannot be cast to > org.apache.pig.backend.hadoop.executionengine.physicalLayer.expressionOperators.PO > Project > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler.getSortCols(MRCompiler.java:1492) > at > org.apache.pig.backend.hadoop.executionengine.mapReduceLayer.MRCompiler.getSamplingJob(MRCompiler.java:1894) > ... 27 more -- This message is automatically generated by JIRA. - You can reply to this email to add a comment to the issue online.