You are viewing a plain text version of this content. The canonical link for it is here.
Posted to issues@drill.apache.org by "Deneche A. Hakim (JIRA)" <ji...@apache.org> on 2015/10/27 19:43:28 UTC
[jira] [Commented] (DRILL-3952) Improve Window Functions
performance when not all batches are required to process the current batch
[ https://issues.apache.org/jira/browse/DRILL-3952?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14976944#comment-14976944 ]
Deneche A. Hakim commented on DRILL-3952:
-----------------------------------------
pull request created: https://github.com/apache/drill/pull/222
> Improve Window Functions performance when not all batches are required to process the current batch
> ---------------------------------------------------------------------------------------------------
>
> Key: DRILL-3952
> URL: https://issues.apache.org/jira/browse/DRILL-3952
> Project: Apache Drill
> Issue Type: Bug
> Components: Execution - Relational Operators
> Affects Versions: 1.2.0
> Reporter: Deneche A. Hakim
> Assignee: Deneche A. Hakim
> Fix For: 1.3.0
>
>
> Currently, the window operator blocks until all batches of current partition to be available. For some queries it's necessary (e.g. aggregate with no order-by in the window definition), but for other cases the window operator can process and pass the current batch downstream sooner.
> Implementing this should help the window operator use less memory and run faster, especially in the presence of a limit operator.
> The purpose of this JIRA is to improve the window operator in the following cases:
> - aggregate, when order-by clause is available in window definition, can process current batch as soon as it receives the last peer row
> - lead can process current batch as soon as it receives 1 more batch
> - lag can process current batch immediately
> - first_value can process current batch immediately
> - last_value, when order-by clause is available in window definition, can process current batch as soon as it receives the last peer row
> - row_number, rank and dense_rank can process current batch immediately
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)