Informatica Powercenter Express - Transformation Basics

Transformation 

It is an object that generates, modifies, or passes data. Transformations can be active/passive or connected/unconnected.

Active transformation changes the number of rows that pass through a transformation or it changes the row type. We cannot connect multiple active transformations or an active and a passive transformation to the same downstream transformation, because the Data Integration Service might not be able to concatenate the rows passed by active transformations.

Passive Transformation does not change the number of rows that pass through the transformation, maintains the transaction boundary, and maintains the row type. 

Connected Transformation is connected to the data flow.

Unconnected transformation is not connected to other transformations in the mapping. An unconnected transformation is called within another transformation, and returns a value to that transformation.

Transformation	Type	Description
Aggregator	Active/Connected	Performs aggregate calculations
Expression	Passive/Connected	Calculates a value
Filter	Active/Connected	Filters data
Java	Active or Passive/ Connected	Executes user logic coded in Java. The byte code for the user logic is stored in the repository
Joiner	Active/Connected	Joins data from different databases or flat file systems
Normalizer	Active/Connected	Processes source rows that contain multiple-occurring data and returns a target row for each instance of the multiple-occurring data
Sorter	Active/Connected	Sorts data based on a sort key
Rank	Active/Connected	Limits records to a top or bottom range
Lookup	Active or Passive/ Connected or Unconnected	Look up and return data from a flat file, logical data object, reference table, relational table, view, or synonym
Update Strategy	Active/Connected	Determines whether to insert, delete, update, or reject rows
Sequence Generator	Passive/Connected	Generates a numeric sequence of values
Union	Active/Connected	Merges data from different databases or flat file systems
SQL	Active or Passive/Connected	Executes SQL queries against a database
Router	Active/Connected	Routes data into multiple transformations based on group conditions