Clean (drop) database before creating schema.
Only dump global objects (users and groups), no databases.
Specifies the hostname of the machine on which the database server is running. If host begins with a slash, it is used as the directory for the UNIX domain socket. The default is taken from the PGHOST environment variable, if set, else a UNIX domain socket connection is attempted.
The port number on which the server is listening. Defaults to the PGPORT environment variable, if set, or a compiled-in default.
Any other command line parameters are passed to the underlying pg_dump calls. This is useful to control some aspects of the output format, but some options such as -f, -t, and dbname should be avoided.
pg_dumpall is a utility for writing out ("dumping") all PostgreSQL databases of a cluster into one script file. The script file contains SQL commands that can be used as input to psql to restore the databases. pg_dumpall also dumps global objects that are common to all databases. (pg_dump does not save these objects.) This includes the information about database users and groups.
Since pg_dumpall reads tables from all databases you will most likely have to connect as a database superuser in order to produce a complete dump. You will need superuser privileges to execute the saved script in order to be allowed to add users and groups, and to create databases.