Vault Database Secret engine Postgres vs SQL user scope

We notice that at connection level, the connection URL for SQL doesn’t have a DB name in it while the Postgres connection has a DB name. (as per documentation)

When creating roles with SQL connection: we can specify which DB we want the dynamic user to be created. (by mentioning the DB name in Creation statements)
when creating roles with Postgres connection: Can we do the same?

Please help with the DB queries/config if that is possible.

If I recall correctly (and apologies its been a few minutes years since I regularly supported PostgreSQL) the connection string requirement here is on the Postgres side:

On creating users for different databases, yes this should be doable, assuming the Postgres role you provided in the database secrets engine configuration is allowed to create new Postgres roles in the target database.

When you create a Vault role, you can specify the Postgres db_name parameter.

Thanks for replying!
The db_name parameter we mention is not the actual DB in the postgres server but the connection name in Vault.