Developer Transformation Guide > Introduction to Transformations > Introduction to Transformations Overview
  

Introduction to Transformations Overview

A transformation is an object that generates, modifies, or passes data.
Informatica Developer provides a set of transformations that perform specific functions. For example, an Aggregator transformation performs calculations on groups of data.
Transformations in a mapping represent the operations that the Data Integration Service performs on the data. Data passes through transformation ports that you link in a mapping or mapplet.
Transformations can be active or passive. Transformations can be connected to the data flow, or they can be unconnected.

Active Transformations

An active transformation changes the number of rows that pass through a transformation. Or, it changes the row type.
For example, the Filter transformation is active, because it removes rows that do not meet the filter condition. The Update Strategy transformation is active, because it flags rows for insert, delete, update, or reject.
You cannot connect multiple active transformations or an active and a passive transformation to the same downstream transformation or transformation input group, because the Data Integration Service might not be able to concatenate the rows passed by active transformations.
For example, one branch in a mapping contains an Update Strategy transformation that flags a row for delete. Another branch contains an Update Strategy transformation that flags a row for insert. If you connect these transformations to a single transformation input group, the Data Integration Service cannot combine the delete and insert operations for the row.

Passive Transformations

A passive transformation does not change the number of rows that pass through the transformation, maintains the transaction boundary, and maintains the row type.
You can connect multiple transformations to the same downstream transformation or to the same transformation input group when all transformations in the upstream branches are passive. The transformation that originates the branch can be active or passive.

Unconnected Transformations

Transformations can be connected to the data flow, or they can be unconnected. An 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.

Multi-Strategy Transformations

A strategy is a set of one or more operations that a transformation can perform on data. You can assign a different set of input ports and output ports to each strategy in a transformation. The transformation stores the strategies that you define in a single transformation object.
Use the Dependencies view to view the ports that each strategy uses.
You can define multiple transformation strategies in the following transformations:

Transformation Descriptions

The Developer tool contains common and data quality transformations. Common transformations are available in Informatica Data Quality and Informatica Data Services. Data quality transformations are available in Informatica Data Quality.
The following table describes each transformation:
Transformation
Type
Description
Address Validator
Active or Passive/
Connected
Verifies and enhances the accuracy of postal address records, and adds information that helps users to select the mail recipients and to deliver the mail.
Association
Active/
Connected
Creates links between the duplicate records that a Match transformation assigns to different clusters.
Aggregator
Active/
Connected
Performs aggregate calculations.
Bad Record Exception
Active/
Connected
Identifies records that might contain data errors, and loads the records to tables that an Analyst tool user can review and update.
Case Converter
Passive/
Connected
Standardizes the case of strings.
Classifier
Passive/
Connected
Writes labels that summarize the information in input port fields. Use when the fields contain significant amounts of text.
Comparison
Passive/
Connected
Generates numeric scores that indicate the degree of similarity between pairs of input strings.
Consolidation
Active/
Connected
Creates a consolidated record from records identified as duplicates by the Match transformation.
Data Masking
Passive/
Connected or Unconnected
Replaces sensitive production data with realistic test data for non-production environments.
Data Processor
Active/
Connected
Processes unstructured and semi-structured file formats in a mapping.
Decision
Passive/
Connected
Evaluates conditions in input data and creates output based on the results of those conditions.
Duplicate Record Exception
Active/
Connected
Identifies records that might contain duplicate information, and loads the records to tables that an Analyst tool user can review and update.
Expression
Passive/
Connected
Calculates a value.
Filter
Active/
Connected
Filters data.
Hierarchical to Relational
Active/
Connected
Processes hierarchical input and transforms it into relational output.
Java
Active or Passive/
Connected
Executes user logic coded in Java. The repository stores the byte code for the user logic.
Joiner
Active/
Connected
Joins data from different databases or flat file systems.
Key Generator
Active/
Connected
Assigns records to groups based on data values in a column that you select.
Labeler
Passive/
Connected
Writes labels that describe the characters or strings in an input port field.
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.
Match
Active/
Connected
Generates scores that indicate the degrees of similarity between input records.
Merge
Passive/
Connected
Reads the data values from multiple input columns and creates a single output column.
Normalizer
Active/
Connected
Processes source rows that contain multiple-occurring data and returns a target row for each instance of the multiple-occurring data.
Output
Passive/
Connected
Defines mapplet output rows.
Parser
Passive/
Connected
Parses the values on an input port into separate output ports based on the types of information that the values contain.
Rank
Active/
Connected
Limits records to a top or bottom range.
Read
Passive/
Connected
Reads data from a source.
Relational to Hierarchical
Active/
Connected
Processes relational input and transforms it into hierarchical output.
REST Web Service Consumer
Active/
Connected
Connects to a REST web service as a web service client to access or transform data
Router
Active/
Connected
Routes data into multiple transformations based on group conditions.
Sequence Generator
Passive/
Connected
Generates a numeric sequence of values.
Sorter
Active/
Connected
Sorts data based on a sort key.
SQL
Active or Passive/
Connected
Executes SQL queries against a database.
Standardizer
Passive/
Connected
Generates standardized versions of input strings.
Union
Active/
Connected
Merges data from different databases or flat file systems.
Update Strategy
Active/
Connected
Determines whether to insert, delete, update, or reject rows.
Web Service Consumer
Active/
Connected
Connects to a web service as a web service client to access or transform data.
Weighted Average
Passive/
Connected
Reads the match scores that a Match transformation generates for the records in a data set, and calculates an average score for each pair of records. You can apply different weights to the scores that the transformation generates for each pair of records.
Write
Passive/
Connected
Represents a target that the mapping writes data to.