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https://issues.apache.org/jira/browse/HIVE-5771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13867338#comment-13867338
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Eric Hanson commented on HIVE-5771:
-----------------------------------
For vectorization_div0, there is the following diff here:
http://bigtop01.cloudera.org:8080/job/PreCommit-HIVE-Build/843/testReport/org.apache.hadoop.hive.cli/TestCliDriver/testCliDriver_vectorization_div0/
< expr: ((cdouble >= -500) and (cdouble < -199))
---
> expr: ((cdouble >= (- 500)) and (cdouble < (- 199)))
The difference is that the unary-minus was constant-folded so one blank is
missing. This is good and not a problem. The query still vectorizes. The
vectorization code has a special-purpose constant folder in it now to do this.
Your code will make that unnecessary. You can safely regenerate the .q.out
file for this test.
> Constant propagation optimizer for Hive
> ---------------------------------------
>
> Key: HIVE-5771
> URL: https://issues.apache.org/jira/browse/HIVE-5771
> Project: Hive
> Issue Type: Improvement
> Components: Query Processor
> Reporter: Ted Xu
> Assignee: Ted Xu
> Attachments: HIVE-5771.1.patch, HIVE-5771.2.patch, HIVE-5771.3.patch,
> HIVE-5771.4.patch, HIVE-5771.5.patch, HIVE-5771.patch
>
>
> Currently there is no constant folding/propagation optimizer, all expressions
> are evaluated at runtime.
> HIVE-2470 did a great job on evaluating constants on UDF initializing phase,
> however, it is still a runtime evaluation and it doesn't propagate constants
> from a subquery to outside.
> It may reduce I/O and accelerate process if we introduce such an optimizer.
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