A database user may have a number of attributes that define its
    privileges and interact with the client authentication system.
    
- superuser
-         A database superuser bypasses all permission checks. Also,
        only a superuser can create new users. To create a database
        superuser, use CREATE USER name
        CREATEUSER.
        
- database creation
-         A user must be explicitly given permission to create databases
        (except for superusers, since those bypass all permission
        checks). To create such a user, use CREATE USER
        name CREATEDB.
        
- password
-         A password is only significant if the client authentication
        method requires the user to supply a password when connecting
        to the database. The password,
        md5, and crypt authentication methods
        make use of passwords. Database passwords are separate from
        operating system passwords. Specify a password upon user
        creation with CREATE USER
        name PASSWORD 'string'. 
        
    A user's attributes can be modified after creation with
    ALTER USER.
    See the reference pages for CREATE USER and
    ALTER USER for details.
   
   A user can also set personal defaults for many of the run-time
   configuration settings described in Section 3.4.  For example, if for some reason you
   want to disable index scans (hint: not a good idea) anytime you
   connect, you can use
ALTER USER myname SET enable_indexscan TO off;
   This will save the setting (but not set it immediately) and in
   subsequent connections it will appear as though SET enable_indexscan
   TO off; had been called right before the session started.
   You can still alter this setting during the session; it will only
   be the default. To undo any such setting, use ALTER USER
   username RESET varname;.