Back in about 1990, IBM realized that customers wanted a data dictionary
that was written using DB2 that could be used to capture entity and
attribute information in the analysis, design, development, and production
support of a project. (Back in those days we had to draw the
entity-relationship diagrams by hand). The DB2 system catalog only stored
information about tables once the application was completely developed, and
allowed little capability for data definitions and domains.

So IBM started a project to develop a product called the Repository that was
so generalized that it not only stored metadata about an application, but it
could store information about anything that could be conceived. The
Repository was so generic that even the tables that stored entities and
attributes were not hard-coded in the Repository..

Even though the Repository was released as a beta product, and IBM even
taught official classes on how it worked, it was never released as a product
and soon became known as the Suppository. It was a gigantic failure and a
huge write off for IBM..

Don't do it. Generic data models are the road to disaster.