Postgres configuration

We are using postgres db and install it with default installation routine.
We also create a new database, called opennms.

Now we want to get rid of the standard first database called postgres.
What is where to configure that this env is running ?

It may need some configuration that for the db connect the db name is explicitly named

It is not recommended to remove the default postgres database.

Not absolutely sure, but doesnโ€™t it contain the PG performance data that we collect for example with: