Tuesday, December 2, 2008

Informatica – How to create a Mapping.

Informatica:Informatica is a powerful ETL tool from Informatica Corporation, a leading provider of enterprise data integration software and ETL softwares. Some of the other popular ETL tools available in market are
Data Stage IBM
Oracle Warehouse Builder Oracle Corporation
Microsoft SQL Server Integration Microsoft
DT/Studio Embarcadero Technologies
Transformation Manager ETL Solutions
Why Informatica?Because it provides many Vanilla mappings taking siebel tables as source within the product
What is a “Mapping”?Mappings represent the data flow between sources and targets. When the Informatica Server executes a session, it uses the instructions configured in the mapping to read, transform, and write data.
Every mapping must contain the following components:
Source definition: It describes the characteristics of a source table or file.Transformation: How to modify data before writing it to targets. Use different transformation objects to on the source data and obtain different results.Target definition: It defines the target table or flat file.Connectors: Connect sources, targets, and transformations so the Informatica Server can move the data as it transforms it.
What is Transformation?Transformation is the core or the most important function of ETL process it determines what to do with the source data before sending to destination.
Now, we are done with the theory hence lets get our hands on practical. Step by step procedure given below has been tested on Informatica version 6.2.2
How to Create a Mapping?
Open the Mapping Designer.
Choose Mappings-Create, or drag a repository object into the workspace.
Enter a name for the new mapping and click OK
Select source tables from the Source Folder (We just need one Source Qualifier, delete other if taking multiple source tables)
Map column from source tables with Source Qualifier and put the SQL Query under Properties tab SQL Query Attribute. SQL query should contain all the fields, joins and table name required for getting the required data.
Under Ports tab the Port (fields) should be in the same order as in the SQL, and data type should be same as in the source table
Now create a transformation Expression
Go to Transformation (Under Tool Bar) Select –> Create Select –> Expression from Dropdown.
Map the ports from Source Qualifier to Expression Transformation.
Map the Ports with the Target Table
In next post we will discuss about different type of Transformation with an example.

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