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From "Ying He (JIRA)" <j...@apache.org>
Subject [jira] Created: (PIG-955) Skewed join generates incorrect results
Date Fri, 11 Sep 2009 19:26:57 GMT
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

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.

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