If you do not specify any parameters, or if both parameters are NULL, the connection IDs for all connections to all databases
running on the database server are returned. If connidparm is less than 0, only the connection ID for the current connection is returned. If connidparm is NULL and dbidparm is less than 0, the connection IDs for just the current database are returned. If connidparm is NULL, and dbidparm is not NULL and its value is greater than or equal to 0, the connection IDs for only that database are returned.
Cloud note: Because of tenant database isolation rules, when this system procedure is run in the cloud it returns only information about
the current tenant database.