Using this option lets you run the server so that it continues running after the current user session ends.
When you start the daemon directly using the -ud option, the database server create the daemon process and return immediately
(exiting and allowing the next command to be executed) before the daemon initializes itself or attempts to open any of the
databases specified in the command.
One advantage of using dbspawn instead of the -ud option is that the dbspawn process does not shut down until it has confirmed
that the daemon has started and is ready to accept requests. If for any reason the daemon fails to start, the exit code for
dbspawn is non-zero.
When you start the database server as a daemon, its permissions are controlled by the current user's unmask setting. It is
recommended that you set the unmask value before starting the database server to ensure that the database server has the appropriate
Do not specify the -um option with the -ud option.