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From camelia c <camelie_1...@yahoo.com>
Subject [GSoc2013] - Outer Join - a question about MergeJoinExec
Date Sat, 07 Sep 2013 11:42:29 GMT
Hello,

I resend You an updated list of questions that I have. For some of the ancient ones, I found
the answer already.

1) In MergeJoinExec, what is the purpose of the innerTupleSlots and outerTupleSlots and can
You please give me an example of how they are filled, based on a dummy data set ?

2) I understood from a talk that the MergeJoinExec has some issues and that Mr Jihoon is trying
to fix them. Can I rely on the current version of MergeJoinExec to extend it for FullOuter_MergeJoinExec
and RightOuter_MergeJoinExec?

3) Given a JoinNode anywhere in the logical query plan, how can we obtain the block name containing
it?
Even for a single-block query, how do we find for a JoinNode that it belongs to @ROOT, for
example?

More precisely, in class OuterJoinRewriteRule, in method
   public LogicalNode visitJoin(LogicalPlan plan, JoinNode joinNode, Stack<LogicalNode>
stack, Integer depth)

I tried to do
    plan.getBlock(joinNode).getName()
but I receive a Null Pointer Exception.



I look forward to receiving Your answer!

Yours sincerely,
Camelia
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