The Test Data Catalogue is a list of standard test data lookups that can be used by project teams to find and make data during testing. Often, teams, developers and testers create lookups using SQL and scripts to find data. The Test Data catalogue allows users to share best practice across teams, well developed SQL and test scripts which are controlled centrally. The other advantage is that if you change a query for example, every automated test would automatically get the updated SQL, allowing changes to be quickly propagated across tests.
Above is an example list of test criteria stored in a Test Data Catalogue within Test Modeller.
Each test criteria can be run against multiple test environments once the criteria is linked to a test. For example, you may want to find a unique live account you wish to close (a feature under test) across a range of different test environments. Whether it be in your development, QA or UAT environments, each allocated account will most likely be different in each of the three. So, although the same test with the same test data criteria is used, each environment would allocate different account numbers once the test is ready to be run.
You can create multiple Test Data Catalogues if you wish and separate them amongst different project teams and environments. The organization of this is up to the local project teams and environment managers.
Above is an example list of Test Data Catalogues in Test Modeller.
Initially it makes more sense to just have one Test Data Catalogue that is shared amongst all development teams, however after a while you may wish to separate into different Catalogues. In the example above the Business Intelligence team have decided to set up their own Test Data Catalogue, their SQL queries are much more complicated than the Development teams and there is little cross sharing.
There is also a batch utility to export and import Test Criteria, see Exporting Allocated Tests.