Daniel Dai updated PIG-483:
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Description:
Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass. This avoids the necessity of having a single reducer. However, in cases where the data is small enough to fit into a single reducer, this is inefficient. For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.
This is a candidate project for Google summer of code 2011. More information about the program can be found at http://wiki.apache.org/pig/GSoc2011
was:Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass. This avoids the necessity of having a single reducer. However, in cases where the data is small enough to fit into a single reducer, this is inefficient. For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.
Labels: gsoc2011 (was: )
PERFORMANCE: different strategies for large and small order bys
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Key: PIG-483
URL: https://issues.apache.org/jira/browse/PIG-483
Project: Pig
Issue Type: Improvement
Affects Versions: 0.2.0
Reporter: Olga Natkovich
Labels: gsoc2011
Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass. This avoids the necessity of having a single reducer. However, in cases where the data is small enough to fit into a single reducer, this is inefficient. For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.
This is a candidate project for Google summer of code 2011. More information about the program can be found at http://wiki.apache.org/pig/GSoc2011
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Key: PIG-483
URL: https://issues.apache.org/jira/browse/PIG-483
Project: Pig
Issue Type: Improvement
Affects Versions: 0.2.0
Reporter: Olga Natkovich
Labels: gsoc2011
Currently pig always does a multi-pass order by where it first determines a distribution for the keys and then orders in a second pass. This avoids the necessity of having a single reducer. However, in cases where the data is small enough to fit into a single reducer, this is inefficient. For small data sets it would be good to realize the small size of the set and do the order by in a single pass with a single reducer.
This is a candidate project for Google summer of code 2011. More information about the program can be found at http://wiki.apache.org/pig/GSoc2011
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