[
https://issues.apache.org/jira/browse/HIVE-5771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14074833#comment-14074833
]
Hari Sankar Sivarama Subramaniyan commented on HIVE-5771:
---------------------------------------------------------
The restriction related to vectorization in ConstantPropagate::transform() can
be lifted once HIVE-7514 is committed. Vectorization will benefit from this
fix, so it is better to make this change.
> 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-5771.10.patch,
> HIVE-5771.11.patch, HIVE-5771.12.patch, HIVE-5771.14.patch,
> HIVE-5771.16.patch, HIVE-5771.2.patch, HIVE-5771.3.patch, HIVE-5771.4.patch,
> HIVE-5771.5.patch, HIVE-5771.6.patch, HIVE-5771.7.patch, HIVE-5771.8.patch,
> HIVE-5771.9.patch, HIVE-5771.patch, HIVE-5771.patch.javaonly
>
>
> 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.
--
This message was sent by Atlassian JIRA
(v6.2#6252)
