There are about 400 application roles defined in our application.
In a production environment there are about 1000 users that have groups of these roles so there are about 7000 role assignments.
We the policy store to be Database based for production environment (as it is recommended by documentation) in order to support clustering Weblogic environment.
Then the hole performance of Enterprise Manager was much worse than in file based. It took about 8 minutes to query the roles. This was happening also in every action , create, assign, remove role.
We run statistics and clean procedure in the database Policy Store but with no improvement.
So Service Request in oracle support is posted and they managed to reproduce it and post a bug: 13597913.
As a workaround we still use File Based Policy Store and synchronize system-jazn-date files between clustered servers.