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https://issues.apache.org/jira/browse/SPARK-5997?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Andrew Ash updated SPARK-5997:
------------------------------
    Description: 
When decreasing partition count with rdd.repartition() or rdd.coalesce(), the 
user has the ability to choose whether or not to perform a shuffle.  However 
when increasing partition count there is no option of whether to perform a 
shuffle or not -- a shuffle always occurs.

This Jira is to create a {{rdd.repartition(largeNum, shuffle=false)}} call that 
performs a repartition to a higher partition count without a shuffle.

The motivating use case is to decrease the size of an individual partition 
enough that the .toLocalIterator has significantly reduced memory pressure on 
the driver, as it loads a partition at a time into the driver.

  was:
When decreasing partition count with rdd.repartition() or rdd.coalesce(), the 
user has the ability to choose whether or not to perform a shuffle.  However 
when increasing partition count there is no option of whether to perform a 
shuffle or not.

This Jira is to create a {{rdd.repartition(largeNum, shuffle=false)}} call that 
performs a repartition to a higher partition count without a shuffle.

The motivating use case is to decrease the size of an individual partition 
enough that the .toLocalIterator has significantly reduced memory pressure on 
the driver, as it loads a partition at a time into the driver.


> Increase partition count without performing a shuffle
> -----------------------------------------------------
>
>                 Key: SPARK-5997
>                 URL: https://issues.apache.org/jira/browse/SPARK-5997
>             Project: Spark
>          Issue Type: Improvement
>          Components: Spark Core
>            Reporter: Andrew Ash
>
> When decreasing partition count with rdd.repartition() or rdd.coalesce(), the 
> user has the ability to choose whether or not to perform a shuffle.  However 
> when increasing partition count there is no option of whether to perform a 
> shuffle or not -- a shuffle always occurs.
> This Jira is to create a {{rdd.repartition(largeNum, shuffle=false)}} call 
> that performs a repartition to a higher partition count without a shuffle.
> The motivating use case is to decrease the size of an individual partition 
> enough that the .toLocalIterator has significantly reduced memory pressure on 
> the driver, as it loads a partition at a time into the driver.



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