[
https://issues.apache.org/jira/browse/DRILL-3754?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14739971#comment-14739971
]
Jinfeng Ni commented on DRILL-3754:
-----------------------------------
[~jnadeau], could you please review the pull request ( the 2nd commit)?
The link in the dev@drill discussion shows the performance improvement with
this patch.
Run unit test / pre-commit and did not see problem.
Thanks!
> Remove redundancy in run-time generated code for common column references.
> ---------------------------------------------------------------------------
>
> Key: DRILL-3754
> URL: https://issues.apache.org/jira/browse/DRILL-3754
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Codegen
> Affects Versions: 1.1.0
> Reporter: Jinfeng Ni
> Assignee: Jinfeng Ni
> Fix For: 1.2.0
>
> Attachments:
> 0002-DRILL-3754-Reduce-redundancy-in-run-time-generated-c.patch
>
>
> When a operator (Filter, project) has expression which refer one same field
> multiple times, Drill will initialize a value vector and do value holder
> assignment for each field reference in the run-time generated code. The
> redundancy might impact the expression evaluation, after the compiled code is
> executed over large number of incoming rows.
> This has been seen in recent performance issue reported on the drill user
> list, where the query contains multiple multiple in list filter conditions.
> In this JIRA, we'll remove the redundancy for the common field reference, so
> that only one initialization and assignment happen in the run-time generated
> code.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
