hadoop-pig-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Brian Donaldson <bria...@gmail.com>
Subject Re: [jira] Updated: (PIG-1408) Annotate explain plans with aliases
Date Fri, 07 May 2010 20:50:59 GMT
Is there a guide anywhere to interpreting the explain command?

On Fri, May 7, 2010 at 1:37 PM, Richard Ding (JIRA) <jira@apache.org> wrote:

>
>     [
> https://issues.apache.org/jira/browse/PIG-1408?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel]
>
> Richard Ding updated PIG-1408:
> ------------------------------
>
>    Attachment: PIG-1408.patch
>
> patch to add aliases to the output plans of the explain command.
>
> > Annotate explain plans with aliases
> > -----------------------------------
> >
> >                 Key: PIG-1408
> >                 URL: https://issues.apache.org/jira/browse/PIG-1408
> >             Project: Pig
> >          Issue Type: Improvement
> >    Affects Versions: 0.7.0
> >            Reporter: Richard Ding
> >            Assignee: Richard Ding
> >             Fix For: 0.8.0
> >
> >         Attachments: PIG-1408.patch
> >
> >
> > PIG-1156 added aliases in Pig scripts to the corresponding
> LogicalOperators and PhysicalOperators. The aliases in the operators,
> however, are not displayed in the output created by the explain command.
> > Since a Pig script can generate many MR jobs, it will be helpful, for
> debugging purposes, to annotate the explain output plans with aliases, so
> that users can correlate the jobs with the statements in their scripts.
> > Here is an example: given the following script
> > {code}
> > A = load 'input';
> > B = group A by $0;
> > C = foreach B generate group, flatten(A);
> > explain C
> > {code}
> > The output without alias annotation is
> > {code}
> > MapReduce node 1-28
> > Map Plan
> > Local Rearrange[tuple]{bytearray}(false) - 1-22
> > |   |
> > |   Project[bytearray][0] - 1-23
> > |
> > |---Load(file:///test/input:org.apache.pig.builtin.PigStorage) -
> 1-19--------
> > Reduce Plan
> > Store(fakefile:org.apache.pig.builtin.PigStorage) - 1-27
> > |
> > |---New For Each(false,true)[bag] - 1-26
> >     |   |
> >     |   Project[bytearray][0] - 1-24
> >     |   |
> >     |   Project[bag][1] - 1-25
> >     |
> >     |---Package[tuple]{bytearray} - 1-21--------
> > Global sort: false
> > {code}
> >
> > While the output with alias annotation will be
> > {code}
> > MapReduce node 1-28
> > Map Plan
> > B: Local Rearrange[tuple]{bytearray}(false) - 1-22
> > |   |
> > |   Project[bytearray][0] - 1-23
> > |
> > |---A: Load(file:///test/input:org.apache.pig.builtin.PigStorage) -
> 1-19--------
> > Reduce Plan
> > C: Store(fakefile:org.apache.pig.builtin.PigStorage) - 1-27
> > |
> > |---C: New For Each(false,true)[bag] - 1-26
> >     |   |
> >     |   Project[bytearray][0] - 1-24
> >     |   |
> >     |   Project[bag][1] - 1-25
> >     |
> >     |---B: Package[tuple]{bytearray} - 1-21--------
> > Global sort: false
> > {code}
>
> --
> This message is automatically generated by JIRA.
> -
> You can reply to this email to add a comment to the issue online.
>
>

Mime
  • Unnamed multipart/alternative (inline, None, 0 bytes)
View raw message