[jira] [Commented] (PIG-2771) Extend LoadPushDown to push limit info to the LoadFunc

["Dmitriy V. Ryaboy (JIRA)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/PIG-2771?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13402366#comment-13402366 ] 

Dmitriy V. Ryaboy commented on PIG-2771:
----------------------------------------

mathias, I think that's been done for 0.10+ 

see PIG-1270
                
> Extend LoadPushDown to push limit info to the LoadFunc
> ------------------------------------------------------
>
>                 Key: PIG-2771
>                 URL: https://issues.apache.org/jira/browse/PIG-2771
>             Project: Pig
>          Issue Type: Improvement
>            Reporter: Mathias Herberts
>            Priority: Minor
>
> It is not uncommon to use LIMIT clauses just after a LOAD, especially during the development phase of new scripts.
> The current behaviour is to do the LIMIT in the map phase just after the LOAD, this means that the output of each Mapper has indeed N records if a 'LIMIT x N' was used, but the LoadFunc has read all the records in its splits.
> A nice optimization would be to push to the LoadFunc the fact that only the first N records are needed, this way the LOAD would terminate as soon as each Mapper have produced N records, which can speed up things quite a bit when input is large.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators: https://issues.apache.org/jira/secure/ContactAdministrators!default.jspa
For more information on JIRA, see: http://www.atlassian.com/software/jira