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From "Alex Behm (Code Review)" <ger...@cloudera.org>
Subject [Impala-ASF-CR] IMPALA-5180: Don't use non-deterministic exprs in partition pruning
Date Tue, 02 May 2017 21:23:11 GMT
Alex Behm has posted comments on this change.

Change subject: IMPALA-5180: Don't use non-deterministic exprs in partition pruning
......................................................................


Patch Set 9:

(1 comment)

http://gerrit.cloudera.org:8080/#/c/6575/9/fe/src/main/java/org/apache/impala/planner/HdfsPartitionPruner.java
File fe/src/main/java/org/apache/impala/planner/HdfsPartitionPruner.java:

Line 112:           !conjunct.contains(Expr.IS_NONDETERMINISTIC_BUILTIN_FN_PREDICATE)) {
> Since we ignore these predicates here, they still get attached to the plan 
Yes, I think so:
* dropping the predicate would be wrong
* evaluating the predicate against partitions would arguably change the query semantics based
on a physical design choice
* the same query against an unpartitioned table might give very different results

So we are left with evaluating the predicate for every row.


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Gerrit-MessageType: comment
Gerrit-Change-Id: I91054c6bf017401242259a1eff5e859085285546
Gerrit-PatchSet: 9
Gerrit-Project: Impala-ASF
Gerrit-Branch: master
Gerrit-Owner: Zach Amsden <zamsden@cloudera.com>
Gerrit-Reviewer: Alex Behm <alex.behm@cloudera.com>
Gerrit-Reviewer: Dan Hecht <dhecht@cloudera.com>
Gerrit-Reviewer: Impala Public Jenkins
Gerrit-Reviewer: Zach Amsden <zamsden@cloudera.com>
Gerrit-HasComments: Yes

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