Informatica - Sequence Generator

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Sequence Generator

Why sequence generator is not directly connected to joiner transformation?

Total Answers and Comments: 5

Last Update: September 30, 2009 Asked by: dl12345

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Submitted by: manoj_pathak

Remember Joiner tx can accept input from only 2 pipelines.

Now only following 2 scenerios possible to have both joiner and Seq Gen tx:
1)2 input pipelines are already connected and then we want to connect Seq Gen to joiner: In this scenerio, the input from Seq Gen will be a input from third pipeline thus, informatica will thro error on that.

2)Only 1 input pipeleine is connected and we want to connect Seq Gen: In this case, ifnromatica will allow you to connect the Seq Gen but then u wont have the mathing CONDITION. thus, this scenerio is practically impossible.

So, both the above scenerios of having Seq Gen with Joiner arent PRACTICALLY possible.

Thanks,
Manoj

Above answer was rated as good by the following members:
avneeshrathor

April 07, 2009 18:01:33

y.dilip

Member Since: April 2009 Contribution: 1

RE: Sequence Generator

Generally Sequence Generators are connected to the targets to minimize the wastage of the generated numbers.

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June 18, 2009 09:53:34

itisanimesh

Member Since: June 2009 Contribution: 4

RE: Sequence Generator

Sequence generator transformation is basically used to generate a unique number for each record which is updated or inserted in the target table. Also it is used if we want to create a unique key in the table and on the basis of this unique key we are going to identify the record within the table. this is the same as the concept of primary key of the table.

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July 16, 2009 05:09:33

sahan

Member Since: July 2009 Contribution: 10

RE: Sequence Generator

In general sequence generator is used to create unique values. Suppose if you connect sequence generator to the joiner after generating numbers to the joiner aging the joiner will split according to the join condition it may give matching rows or unmatching rows then the number of rows is going to change.

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August 06, 2009 05:51:25

itisanimesh

Member Since: June 2009 Contribution: 4

RE: Sequence Generator

In Addition to previous answer

Sequence Generator transformation is a Passive and Connected transformation. It is used to create unique primary key values or cycle through a sequential range of numbers or to replace missing keys.

It has two output ports to connect transformations. By default it has two fields CURRVAL and NEXTVAL(You cannot add ports to this transformation). NEXTVAL port generates a sequence of numbers by connecting it to a transformation or target. CURRVAL is the NEXTVAL value plus one or NEXTVAL plus the Increment By value.

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September 30, 2009 15:08:28

manoj_pathak

Member Since: September 2009 Contribution: 2

RE: Sequence Generator

Remember Joiner tx can accept input from only 2 pipelines.

Now only following 2 scenerios possible to have both joiner and Seq Gen tx:
1)2 input pipelines are already connected and then we want to connect Seq Gen to joiner: In this scenerio the input from Seq Gen will be a input from third pipeline thus informatica will thro error on that.

2)Only 1 input pipeleine is connected and we want to connect Seq Gen: In this case ifnromatica will allow you to connect the Seq Gen but then u wont have the mathing CONDITION. thus this scenerio is practically impossible.

So both the above scenerios of having Seq Gen with Joiner arent PRACTICALLY possible.

Thanks
Manoj

Is this answer useful? Yes | No

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