drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jason Altekruse (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-2395) Improve interpreted expression evaluation to only call the setup method once per batch
Date Fri, 06 Mar 2015 22:06:38 GMT

    [ https://issues.apache.org/jira/browse/DRILL-2395?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14350992#comment-14350992
] 

Jason Altekruse commented on DRILL-2395:
----------------------------------------

Another issue with the current evaluation model is that constant values that require allocating
an off heap buffer (such as varchar or varbinary literals) are allocating a new buffer for
the execution of the expression on each record. I believe the work to make sure literals are
only materialized once should subsume this, but it should be noted that when this other work
is done to optimize execution on a full record batch, we should make sure no excessive memory
is being allocated for each record processed.

> Improve interpreted expression evaluation to only call the setup method once per batch
> --------------------------------------------------------------------------------------
>
>                 Key: DRILL-2395
>                 URL: https://issues.apache.org/jira/browse/DRILL-2395
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Functions - Drill
>            Reporter: Jason Altekruse
>            Assignee: Jason Altekruse
>            Priority: Minor
>
> This enhancement request came out of the review for a patch for DRILL-2060. Copied below
is the discussion from there:
> Jinfeng:
> Do you have a plan to move setup() call into places such that setup() will be called
once for each VectorAccessible input?
> In the code compile + evaluation model, doSetup() will be called per batch, in stead
of per row.
> Jason:
> I have started working on a fix for this. Its a little complicated with setting constant
inputs before the setup method is called. I'm trying to figure out the best way to share code
with the rest of the input passing used in the EvalVisitor. Would you be okay with this being
opened as an enhancement request to be merged a little later? Considering the current use
of the interpreter this won't have an impact on any actual queries today.



--
This message was sent by Atlassian JIRA
(v6.3.4#6332)

Mime
View raw message