hadoop-pig-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Ashutosh Chauhan (JIRA)" <j...@apache.org>
Subject [jira] Updated: (PIG-865) Performance: Unnnecessary computation in FRJoin
Date Fri, 03 Jul 2009 06:22:47 GMT

     [ https://issues.apache.org/jira/browse/PIG-865?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]

Ashutosh Chauhan updated PIG-865:
---------------------------------

    Attachment: pig-865_v2.patch

In discussions with Pradeep, it came out that creating new objects may be a better choice
then reusing the same reference because reusing same reference again and again may move it
to older generation which may result in it taking longer to get garbage collected. Moreover,
it seems it also depends on skewness of distribution of keys in data. Thus, its not clear
which is a better choice here. Thus, not including 
that change in this jira. Other suggested changes are incorporated in the patch.

> Performance: Unnnecessary computation in FRJoin
> -----------------------------------------------
>
>                 Key: PIG-865
>                 URL: https://issues.apache.org/jira/browse/PIG-865
>             Project: Pig
>          Issue Type: Improvement
>          Components: impl
>    Affects Versions: 0.3.0
>            Reporter: Ashutosh Chauhan
>            Assignee: Ashutosh Chauhan
>            Priority: Minor
>             Fix For: 0.4.0
>
>         Attachments: pig-865.patch, pig-865_v2.patch
>
>
> In POFRJoin implementation POLocalRearrange is used to extract join keys from the input
tuples. If keys match then to perform actual join input tuples are fed to Foreach which does
a cross on its inputs. After keys are extracted using POLocalRearrange output; function getValueTuple(POLocalRearrange
lr, Tuple tuple) is called to reconstruct the input tuple. It seems that this function call
is unnecessary since we already have input tuple at that time. 
> This is not a bug, but since this function would get called for every tuple, if it is
eliminated, it should certainly help to improve performance. 

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


Mime
View raw message