drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Jacques Nadeau (JIRA)" <j...@apache.org>
Subject [jira] [Updated] (DRILL-351) MergeJoin physical operator projects columns that may not be needed
Date Sun, 04 Jan 2015 21:28:53 GMT

     [ https://issues.apache.org/jira/browse/DRILL-351?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Jacques Nadeau updated DRILL-351:
---------------------------------
    Issue Type: Improvement  (was: Bug)

> MergeJoin physical operator projects columns that may not be needed
> -------------------------------------------------------------------
>
>                 Key: DRILL-351
>                 URL: https://issues.apache.org/jira/browse/DRILL-351
>             Project: Apache Drill
>          Issue Type: Improvement
>          Components: Execution - Operators
>            Reporter: Aman Sinha
>             Fix For: Future
>
>
> The MergeJoin physical operator currently projects all columns from the left and right
inputs with the assumption that a subsequent Project will drop the unnecessary columns. This
is sub-optimal because we incur the memory and cpu overhead of populating the output record
batch value vectors for those columns. Ideally, the operator could keep track of the columns
that are needed by the parent (downstream) operator and only project those  columns. 



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

Mime
View raw message