hadoop-pig-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Olga Natkovich (JIRA)" <j...@apache.org>
Subject [jira] Commented: (PIG-955) Skewed join generates incorrect results
Date Fri, 11 Sep 2009 20:44:58 GMT

    [ https://issues.apache.org/jira/browse/PIG-955?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12754335#action_12754335
] 

Olga Natkovich commented on PIG-955:
------------------------------------

+1. Changes look good. Just need to wait for test results

> Skewed join generates  incorrect results 
> -----------------------------------------
>
>                 Key: PIG-955
>                 URL: https://issues.apache.org/jira/browse/PIG-955
>             Project: Pig
>          Issue Type: Improvement
>            Reporter: Ying He
>         Attachments: PIG-955.patch
>
>
> Fragmented replicated join has a few limitations:
>  - One of the tables needs to be loaded into memory
>  - Join is limited to two tables
> Skewed join partitions the table and joins the records in the reduce phase. It computes
a histogram of the key space to account for skewing in the input records. Further, it adjusts
the number of reducers depending on the key distribution.
> We need to implement the skewed join in pig.

-- 
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