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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 Sat, 28 Jan 2017 03:39:47 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 2:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/5768/2/fe/src/main/java/org/apache/impala/analysis/CaseExpr.java
File fe/src/main/java/org/apache/impala/analysis/CaseExpr.java:

Line 384:     // Otherwise, take a max over all the outputs as well as all the slotrefs that
> would this make us throw away information where we're not doing that today?
Yes. The alternative is to take the max over the 'then/else exprs' and ignore those with an
NDV of -1. This is more similar (but still different) than the old behavior.


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Gerrit-MessageType: comment
Gerrit-Change-Id: I21dbdaad8452b7e58c477612b47847dccd9d98d2
Gerrit-PatchSet: 2
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Joe McDonnell <joemcdonnell@cloudera.com>
Gerrit-Reviewer: Alex Behm <alex.behm@cloudera.com>
Gerrit-Reviewer: Joe McDonnell <joemcdonnell@cloudera.com>
Gerrit-Reviewer: Marcel Kornacker <marcel@cloudera.com>
Gerrit-HasComments: Yes

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