[PIG-401] SplitIntroducer does not handle some cases correctly

• Type: Bug
• Status: Closed
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 0.2.0
• Fix Version/s: 0.2.0
• Assignee: Alan Gates
• Reporter: Pradeep Kamath
• Created: 27/Aug/08 22:59
• Updated: 24/Mar/10 22:04
• Resolved: 05/Sep/08 23:33

Description

The splitIntroducer does not handle the following cases correctly:

• As soon as SplitIntroducer sees an operator which does NOT have multiple outputs it stops - it should still recursively check the successors:
  Current code which needs to change:

          List<LogicalOperator> sucs = mPlan.getSuccessors(root);
          if(sucs==null) return; 
          int size = sucs.size();
          if(size==0 || size==1) return;  --> THIS should change to recursively process the succesor if it exists(size == 1 case)
  

• If there are more than one operators in the plan which need implicit splits to be introduced
• If the new SPLIT operator is introduced before a cogroup, the cogroup's inner map for it's inputs and GroupBy expressions needs to be updated
• The kind of changes need for cogroup maybe needed for some other operators

I started looking at it some and have a patch for the first two issues - UNTESTED which I am attaching to this issue