[jira] Commented: (PIG-750) Use combiner when a mix of algebraic and non-algebraic functions are used

[David Ciemiewicz (JIRA)]

[ 
https://issues.apache.org/jira/browse/PIG-750?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12700195#action_12700195
 ] 

David Ciemiewicz commented on PIG-750:
--

Also consider the application of a scalar function to the result of an 
aggregation function:

3) foreach X generate EXP(AVG(b))

 Use combiner when a mix of algebraic and non-algebraic functions are used
 -

 Key: PIG-750
 URL: https://issues.apache.org/jira/browse/PIG-750
 Project: Pig
  Issue Type: Improvement
Reporter: Amir Youssefi
Priority: Minor

 Currently Pig uses combiner when all a,b, c,... are algebraic (e.g. SUM, AVG 
 etc.) in foreach:
 foreach X generate a,b,c,... 
  It's a performance improvement if it uses combiner when a mix of algebraic 
 and non-algebraic functions are used as well.

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[jira] Commented: (PIG-750) Use combiner when a mix of algebraic and non-algebraic functions are used

[Amir Youssefi (JIRA)]

[ 
https://issues.apache.org/jira/browse/PIG-750?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=12699023#action_12699023
 ] 

Amir Youssefi commented on PIG-750:
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Other use-cases we need have in unit tests:

1) foreach X generate SUM(a) * AVG(b), ...

2) foreach X generate 1 / SUM(a) 

Currently, there is a work-around suggested to have all algebraic functions 
calculated in a foreach and then more expressions/mixes are calculated in a 
second foreach. This way combiner is used in the first foreach and we get 
combiner speed-up.

 Use combiner when a mix of algebraic and non-algebraic functions are used
 -

 Key: PIG-750
 URL: https://issues.apache.org/jira/browse/PIG-750
 Project: Pig
  Issue Type: Improvement
Reporter: Amir Youssefi
Priority: Minor

 Currently Pig uses combiner when all a,b, c,... are algebraic (e.g. SUM, AVG 
 etc.) in foreach:
 foreach X generate a,b,c,... 
  It's a performance improvement if it uses combiner when a mix of algebraic 
 and non-algebraic functions are used as well.

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You can reply to this email to add a comment to the issue online.