Thursday, March 14, 2013

Transformations in Informatica 9

What is a Transformation

A transformation is a repository object which reads the data, modifies the data and passes the data. Transformations in a mapping represent the operations that the integration service performs on the data.

Transformations can be classified as active or passive, connected or unconnected.

Active Transformations:

A transformation can be called as an active transformation if it performs any of the following actions.
  • Change the number of rows: For example, the filter transformation is active because it removes the rows that do not meet the filter condition. All multi-group transformations are active because they might change the number of rows that pass through the transformation.
  • Change the transaction boundary: The transaction control transformation is active because it defines a commit or roll back transaction.
  • Change the row type: Update strategy is active because it flags the rows for insert, delete, update or reject.

Note: You cannot connect multiple active transformations or an active and passive transformation to the downstream transformation or transformation same input group. This is because the integration service may not be able to concatenate the rows generated by active transformations. This rule is not applicable for sequence generator transformation.

Passive Transformations:

Transformations which does not change the number of rows passed through them, maintains the transaction boundary and row type are called passive transformation.

Connected Transformations:

Transformations which are connected to the other transformations in the mapping are called connected transformations.

Unconnected Transformations:

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

The below table lists the transformations available in Informatica version 9:

AggregatorActive/ConnectedPerforms aggregate calculations.
ApplicationSourceQualifierActive/ConnectedRepresents therows that the Integration Service reads from an application, such as an ERP source, when it runs a session.
CustomActiveorPassive/ConnectedCalls a procedure in a shared library or DLL.
DataMaskingPassive/ConnectedReplaces sensitive production data with realistic test data for non-production environments.
ExpressionPassive/ConnectedCalculates a value.
ExternalProcedurePassive/ConnectedorUnconnectedCalls a procedure in a shared library or in the COM layer of Windows.
FilterActive/ConnectedFilters data.
HTTPPassive/ConnectedConnects to an HTTP server to read or update data.
InputPassive/ConnectedDefines mapplet input rows. Available in the Mapplet Designer
JavaActiveorPassive/ConnectedExecutes user logic coded in Java.The byte code for the user logic is stored in the repository
JoinerActive/ConnectedJoins data from different databases or flat file systems.
LookupActiveorPassive/ConnectedorUnconnectedLookup and return data from a flat file, relational table, view, or synonym.
NormalizerActive/ConnectedSource qualifier for COBOL sources. Can also use in the pipeline to normalize data from relational or flat file sources.
OutputPassive/ConnectedDefines mapplet output rows. Available in the Mapplet Designer.
RankActive/ConnectedLimits records to a top or bottom range.
RouterActive/ConnectedRoutes data into multiple transformations based on group conditions.
SequenceGeneratorPassive/ConnectedGenerates primary keys.
SorterActive/ConnectedSorts data based on a sort key.
SourceQualifierActive/ConnectedRepresents the rows that the Integration Service reads from a relational or flat file source when it runs a session.
SQLActiveorPassive/ConnectedExecutes SQL queries against a database.
StoredProcedurePassive/ConnectedorUnconnectedCalls a stored procedure.
TransactionControlActive/ConnectedDefines commit and rollback transactions.
UnionActive/ConnectedMerges data from different databases or flat file systems.
UnstructuredDataActiveorPassive/ConnectedTransforms data in unstructured and semi-structured formats.
UpdateStrategyActive/ConnectedDetermines whether to insert, delete, update, or reject rows.
XMLGeneratorActive/ConnectedReads data from one or more input ports and outputs XML through a single output port.
XMLParserActive/ConnectedReads XML from one input port and outputs data to one or more output ports.
XMLSourceQualifierActive/ConnectedRepresents the rows that the Integration Service reads from an XML source when it runs a session.

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