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From "Alex Behm (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-4792: Fix number of distinct values for a CASE with constant outputs
Date Mon, 23 Jan 2017 23:29:33 GMT
Alex Behm has posted comments on this change.

Change subject: IMPALA-4792: Fix number of distinct values for a CASE with constant outputs
......................................................................


Patch Set 1:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/5768/1//COMMIT_MSG
Commit Message:

Line 12: There is a limitation to this fix:
To fix this we might consider changing Expr.computeNumDistinctValues() to compute the max
NDV over all children, instead of the max NDV over the contained SlotRefs.

I think that should yield the same NDV for those Exprs where the original SlotRef-based NDV
made sense.

What do you think?


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Gerrit-MessageType: comment
Gerrit-Change-Id: I21dbdaad8452b7e58c477612b47847dccd9d98d2
Gerrit-PatchSet: 1
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Joe McDonnell <joemcdonnell@cloudera.com>
Gerrit-Reviewer: Alex Behm <alex.behm@cloudera.com>
Gerrit-HasComments: Yes

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