What are Aggregate transformation?

Aggregator transformation allows you to perform aggregate calculations, such as averages and sums.

Editorial / Best Answer

Answered by: Praveen vasudev

  • Sep 12th, 2005


Aggregator transform is m uch like the Group by clause in traditional SQL.

this particular transform is a connected/active transform which can take the incoming data form the mapping pipeline and group them based on the group by ports specified and can caculated aggregate funtions like ( avg, sum, count, stddev....e.tc) for each of those groups.

From a performanace perspective if your mapping has an AGGREGATOR transform use filters and sorters very early in the pipeline if there is any need for them.

veepee

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Praveen vasudev

  • Sep 12th, 2005
 

Aggregator transform is m uch like the Group by clause in traditional SQL.

this particular transform is a connected/active transform which can take the incoming data form the mapping pipeline and group them based on the group by ports specified and can caculated aggregate funtions like ( avg, sum, count, stddev....e.tc) for each of those groups.

From a performanace perspective if your mapping has an AGGREGATOR transform use filters and sorters very early in the pipeline if there is any need for them.

veepee

sithusithu

  • Jan 19th, 2006
 

The Aggregator transformation allows you to perform aggregate calculations, such as averages and sums. The Aggregator transformation is unlike the Expression transformation, in that you can use the Aggregator transformation to perform calculations on groups.

Cheers,

Sithu

siraj.khan

  • Aug 3rd, 2007
 

Aggregate Transformation is used to aggregate the data Colum wise..The only difference between the Aggregate and Expression transformation is that Aggregate transformation sorts the data Row wise where as Expression transformation sorts the data Column wise.

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pallavi18

  • Jan 18th, 2010
 

The Aggregator transformation performs aggregate calculations, such as averages and sums.

The Aggregator transformation is unlike the Expression transformation, in that you use the Aggregator transformation to perform calculations on groups.

The Expression transformation permits you to perform calculations on a row-by-row basis only.

It is Active transformation which is used to perform aggregate calculation such as sum AVG, MAX and MIN.

As performance prospective if your mapping contains aggregate transformation enable sorted input port and make sure that your sorting the data prior to aggregate transformation by using sorter or if viable sort the data at SQ level.

shr_4

  • Oct 26th, 2010
 

To perform Group by calculations  we use Aggregator Transformation.

It perform calculations similar to Expression Transformation.

But difference  between both is that 
Aggregator Transformation:-  Perform calculations on Group
ex:- sum,avg,count
Expression Transformation:-  Perform calculations on row-by-row basis.
ex:- concat,isnull

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sivakp

  • Mar 13th, 2011
 

1. Aggrigator transformation allows to perform aggrigate calculation, such as SUM, MAX, MIN, FIRST, LAST
2. Aggrigator transformation allows to perform aggrigate calculation of group.

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