Symantec Endpoint Protection 11 (short: SEP11) has a database in which it stocks everything from client properties, virus definitions and more. At the installation, you could either select to use an external data source, or its internal database format. When the database is in service for a while, it can grow very large, depending on the number of clients you've got. But it is possible to shrink (= compact) it, which, in certain cases, could save you several hundreds of MB.

Notice

The problem of a overly large database was addressed in Maintenance Release 2, where the compact operation is do  ...