A mapping parameter represents a constant value that you can define before running a session using a parameter file. Sometimes, business requirement may make it necessary to modify the parameter file frequently before running the session. In such cases, parameter files can be generated dynamically without directly editing them.Using a database table to maintain parameter file values can offer the following benefits

• Flexibility in maintaining the parameter files.
• Reduces the overhead for the admin support to change the parameter file every time a value of a parameter changes.
• Ease the deployment as all the parameters are maintained in database tables and a PowerCenter session can generate the parameter file in the required format automatically.

Implementation GuidelineFor this, 4 tables are to be created in the database:

1. FOLDER table ? Contains entries for each folder.
2. WORKFLOWS table ? Contains the list of each workflow but with a reference to the FOLDERS table to say which folder a workflow belongs to.
3. PARAMETERS table - Holds all the parameter names without reference to folder/workflow.
4. PARAMETER_VALUES table - Holds the parameter of each session with references to PARAMETERS table for parameter name and WORKFLOWS table for the workflow name. When the session name is NULL, it means the parameter is a workflow variable which can be used across all the sessions in the workflow.

The create table script for these tables are part of the attachment. The script also contains the a view that gets all the parameter file rows in the required format. For an Informatica workflow parameter file which can be used by any session in the workflow, the format in which the parameter file has to be created is: [Folder_name.WF:Workflow_Name]$$parameter_name1=value$$parameter_name2=valueFor a session parameter which can be used by the particular session, the format in which the parameter file has to be created is: [Folder_name.WF:Workflow_Name.ST:Session_Name]$$parameter_name1=value$$parameter_name2=value