Thursday, February 25, 2016

Joiner Transformation In Informatica

Joiner Transformation

Ø  Joiner can be used to join data coming from two pipelines of a mapping.
Ø  Using joiner transformation you can join data coiming from two different types of source systems
Ø  Usually a join mapping contains two input pipelines include a master pipeline and a detail pipeline or a master and a detail branch.
Ø  The master pipeline ends at the Joiner transformation, while the detail pipeline continues to the target
Ø  Generally in a join mapping Informatica Caches all the data from Master source before it starts the join operation, Once the Master Caches build is completed then it reads data from Detail source/pipeline and joins the data.
Ø  So as a best practice it is always good to configure the source with less number of records as Master for the Joiner, so that it caches less number of records. This improves joiner performance significantly when processing huge volumes of records.
Ø  By default, when you add ports to a Joiner transformation, the ports from the first source pipeline display as detail sources.
Ø  Adding the ports from the second source pipeline sets them as master sources.

  A Joiner transformation supports the below types of joins:

Normal join, Master outer join, Detail outer Join, Full outer join

Ø  A normal or master outer join performs faster than a full outer or detail outer join.
Ø  To improve performance for an unsorted Joiner transformation, use the source with fewer rows as the master source.
Ø  To improve performance for a sorted Joiner transformation, use the source with fewer duplicate key values as the master.
Ø  You can also use a joiner to join data which is orginating from the same source
Ø  You cannot use a Joiner transformation when either input pipeline contains an Update Strategy transformation
Ø  You cannot use a Joiner transformation if you connect a Sequence Generator transformation directly before the Joiner transformation.
Ø  If the both source of the joiner are relational and they are of same type it is always better to perform join operation at database level using Source Qualifier transformation.
Ø  If it is possible implement join operation on sorted data.
For an unsorted Joiner transformation, designate the source with fewer rows as the master source and for a sorted Joiner transformation, designate the source with fewer duplicate key values as the master source

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