merge join should handle compressed bz2 sorted files
----------------------------------------------------

                 Key: PIG-930
                 URL: https://issues.apache.org/jira/browse/PIG-930
             Project: Pig
          Issue Type: Bug
            Reporter: Pradeep Kamath


There are two issues - POLoad which is used to read the right side input does 
not handle bz2 files right now. This needs to be fixed.
Further inn the index map job we bindTo(startOfBlockOffSet) (this will 
internally discard first tuple if offset > 0). Then we do the following:

{noformat}
While(tuple survives pipeline) {

  Pos =  getPosition()

  getNext() 

  run the tuple  through pipeline in the right side which could have filter

}

Emit(key, pos, filename).
{noformat}
 
Then in the map job which does the join, we bindTo(pos > 0 ? pos  1 : pos) (we 
do pos -1 because bindTo will discard first tuple for pos> 0). Then we do 
getNext()
Now in bz2 compressed files, getPosition() returns a position which is not 
really accurate. The problem is it could be a position in the middle of a 
compressed bz2 block. Then when we use that position to bindTo() in the final 
map job, the code would first hunt for a bz2 block header thus skipping the 
whole current bz2 block. 


-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.

Reply via email to