Data Warehouse Interview-1

what is the metadata extension?

Informatica allows end users and partners to extend the metadata stored in the repository by associating information with individual objects in the repository. For example, when you create a mapping, you can store your contact information with the mapping. You associate information with repository metadata using metadata extensions.

Informatica Client applications can contain the following types of metadata extensions:

• Vendor-defined. Third-party application vendors create vendor-defined metadata extensions. You can view and change the values of vendor-defined metadata extensions, but you cannot create, delete, or redefine them.
• User-defined. You create user-defined metadata extensions using PowerCenter/PowerMart. You can create, edit, delete, and view user-defined metadata extensions. You can also change the values of user-defined extensions.

What are the various test procedures used to check whether the data is loaded in the backend, performance of the mapping, and quality of the data loaded in INFORMATICA.

The best procedure to take a help of debugger where we monitor each and every process of mappings and how data is loading based on conditions breaks.

explain the process of extracting data from source systems,storing in ODS and how data modelling is done.

There are various ways of Extracting Data from Source Systems.For example , You can use a DATA step, an Import Process .It depends with your input data styles. What kind of File/database it is residing in. Storing ur data in an ODS can be done thru an ODS stmt/export stmt/FILE stmt, again which depends on the file & data format ,You want your output to be in.

where do we use connected and un connected loops

If return port only one then we can go for unconnected. More than one return port is not possible with Unconnected. If more than one return port then go for Connected.