Wednesday, February 24, 2016

Union Transformation In Informatica

Union Transformation

Ø  The Union transformation is a multiple input group transformation that you use to merge data from multiple pipelines or pipeline branches into one pipeline branch.
Ø  It merges data from multiple sources similar to the UNION ALL SQL statement to combine the results from two or more SQL statements.
Ø  Similar to the UNION ALL statement, the Union transformation does not remove duplicate rows.
Ø  You can connect heterogeneous sources to a Union transformation. The transformation merges sources with matching ports and outputs the data from one output group with the same ports as the input groups
Ø  A Union transformation can have multiple input groups, but only one output group. 
Ø  All input groups and the output group must have matching ports. The precision, datatype, and scale must be identical across all groups.
Ø  The Union transformation does not remove duplicate rows. To remove duplicate rows, you must add another transformation such as a Router or Filter transformation after UNION transformation.
Ø  You cannot use a Sequence Generator or Update Strategy transformation upstream from a Union transformation.

Ø  Union transformation can be used to merge data orginating from different types of sources i.e. all the sources for Union may ot orginate from same type of data source.

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