Metadata Extensions in Informatica

For every repository object corresponding  metadata is stored in the repository.

In addition to the existing metadata for an object in the repository you can add your own metadata.

You can extend the metadata stored in the repository by associating information with individual repository objects.
For example, you may want to store contact information with the sources you create. If you create an Aggregator transformation, you may want to store an email address with that transformation. You associate information with repository objects using metadata extensions.

You can create metadata extensions for the following objects in the Designer:

§  Source definitions

§  Target definitions

§  Transformations

§  Mappings

§  Mapplets

Metadata for a repository object can be two type

1. Vendor-defined and

2. User-defined 

vendor-defined metadata extensions:

We can view and change the values of vendor-defined metadata extensions, but we cannot create, delete, or redefine them.

User-defined metadata extensions:

We can create, edit, delete, and view user-defined metadata extensions and change their values also.

Creating Metadata Extensions

We can create user-defined metadata extensions of two types

1.Reusable Metadata Extensions: Can be associated with all repository objects of a certain type, such as all source definitions or all Expression transformations.

2. Non Reusable Metadata Extensions: Can be associated with a single repository object, such as one target definition or one mapping.

To create a metadata extension:
1. Open the appropriate Designer tool.
2. Drag the appropriate object into the workspace.
3. Double-click the title bar of the object to edit it.

Note: If the object is a mapping or mapplet,    click   Mappings >Metadata Extensions or       Mapplets  > Metadata Extensions.

4. Click the Metadata Extensions tab.

5. Click the Add button.

    A new row appears in the User Defined Metadata Extension Domain.

6. Enter the following information:

Expression Name-- Any unique name. Naming rules  applicable

Data type--String or Numeric or Boolean

Precision--Maximum length for string metadata extensions.

Value-- Depending on the Metadata Extension Data type.

Reusable--Makes the metadata extension reusable or non-reusable.

Difference between Reusable and Non Reusable Metadata Extensions:

Reusable Metadata Extensions	Non Reusable Metadata Extensions
Can associate with all repository objects of a certain type	Can associate  with a single repository object
Can’t promote to  Non Reusable	Can promote to Reusable
Only VALUE  can be changed	All properties can be changed
Can be created from Repository Manager	Created only from the Designer
Can be deleted from Repository Manager	Deleted only from the Designer