A database role can have a number of attributes that define its privileges and interact with the client authentication system.
        Only roles that have the LOGIN attribute can be used
        as the initial role name for a database connection.  A role with
        the LOGIN attribute can be considered the same
        as a “database user”.  To create a role with login privilege,
        use either:
CREATE ROLEnameLOGIN; CREATE USERname;
        (CREATE USER is equivalent to CREATE ROLE
        except that CREATE USER includes LOGIN by
        default, while CREATE ROLE does not.)
       
        A database superuser bypasses all permission checks, except the right
        to log in.  This is a dangerous privilege and should not be used
        carelessly; it is best to do most of your work as a role that is not a
        superuser.  To create a new database superuser, use CREATE
        ROLE .  You must do
        this as a role that is already a superuser.
       name SUPERUSER
        A role must be explicitly given permission to create databases
        (except for superusers, since those bypass all permission
        checks). To create such a role, use CREATE ROLE
        .
       name CREATEDB
        A role must be explicitly given permission to create more roles
        (except for superusers, since those bypass all permission
        checks). To create such a role, use CREATE ROLE
        .
        A role with name CREATEROLECREATEROLE privilege can alter and drop
        roles which have been granted to the CREATEROLE
        user with the ADMIN option. Such a grant occurs
        automatically when a CREATEROLE user that is not
        a superuser creates a new role, so that by default, a
        CREATEROLE user can alter and drop the roles
        which they have created.
        Altering a role includes most changes that can be made using
        ALTER ROLE, including, for example, changing
        passwords.  It also includes modifications to a role that can
        be made using the COMMENT and
        SECURITY LABEL commands.
       
        However, CREATEROLE does not convey the ability to
        create SUPERUSER roles, nor does it convey any
        power over SUPERUSER roles that already exist.
        Furthermore, CREATEROLE does not convey the power
        to create REPLICATION users, nor the ability to
        grant or revoke the REPLICATION privilege, nor the
        ability to modify the role properties of such users.  However, it does
        allow ALTER ROLE ... SET and
        ALTER ROLE ... RENAME to be used on
        REPLICATION roles, as well as the use of
        COMMENT ON ROLE,
        SECURITY LABEL ON ROLE,
        and DROP ROLE.
        Finally, CREATEROLE does not
        confer the ability to grant or revoke the BYPASSRLS
        privilege.
       
        A role must explicitly be given permission to initiate streaming
        replication (except for superusers, since those bypass all permission
        checks). A role used for streaming replication must
        have LOGIN permission as well. To create such a role, use
        CREATE ROLE .
       name REPLICATION
        LOGIN
        A password is only significant if the client authentication
        method requires the user to supply a password when connecting
        to the database. The password and
        md5 authentication methods
        make use of passwords. Database passwords are separate from
        operating system passwords. Specify a password upon role
        creation with CREATE ROLE
        .
       name PASSWORD 'string'
        A role inherits the privileges of roles it is a member of, by default.
        However, to create a role which does not inherit privileges by
        default, use CREATE ROLE .  Alternatively, inheritance can be overridden
        for individual grants by using name
        NOINHERITWITH INHERIT TRUE
        or WITH INHERIT FALSE.
       
        A role must be explicitly given permission to bypass every row-level security (RLS) policy
        (except for superusers, since those bypass all permission checks).
        To create such a role, use CREATE ROLE  as a superuser.
       name BYPASSRLS
        Connection limit can specify how many concurrent connections a role can make.
        -1 (the default) means no limit. Specify connection limit upon role creation with
        CREATE ROLE .
       name CONNECTION LIMIT 'integer'
    A role's attributes can be modified after creation with
    ALTER ROLE.
    See the reference pages for the CREATE ROLE
    and ALTER ROLE commands for details.
   
A role can also have role-specific defaults for many of the run-time configuration settings described in Chapter 19. For example, if for some reason you want to disable index scans (hint: not a good idea) anytime you connect, you can use:
ALTER ROLE myname SET enable_indexscan TO off;
   This will save the setting (but not set it immediately).  In
   subsequent connections by this role it will appear as though
   SET enable_indexscan TO off had been executed
   just before the session started.
   You can still alter this setting during the session; it will only
   be the default. To remove a role-specific default setting, use
   ALTER ROLE .
   Note that role-specific defaults attached to roles without
   rolename RESET varnameLOGIN privilege are fairly useless, since they will never
   be invoked.
  
   When a non-superuser creates a role using the CREATEROLE
   privilege, the created role is automatically granted back to the creating
   user, just as if the bootstrap superuser had executed the command
   GRANT created_user TO creating_user WITH ADMIN TRUE, SET FALSE,
   INHERIT FALSE. Since a CREATEROLE user can
   only exercise special privileges with regard to an existing role if they
   have ADMIN OPTION on it, this grant is just sufficient
   to allow a CREATEROLE user to administer the roles they
   created. However, because it is created with INHERIT FALSE, SET
   FALSE, the CREATEROLE user doesn't inherit the
   privileges of the created role, nor can it access the privileges of that
   role using SET ROLE. However, since any user who has
   ADMIN OPTION on a role can grant membership in that
   role to any other user, the CREATEROLE user can gain
   access to the created role by simply granting that role back to
   themselves with the INHERIT and/or SET
   options. Thus, the fact that privileges are not inherited by default nor
   is SET ROLE granted by default is a safeguard against
   accidents, not a security feature. Also note that, because this automatic
   grant is granted by the bootstrap superuser, it cannot be removed or changed by
   the CREATEROLE user; however, any superuser could
   revoke it, modify it, and/or issue additional such grants to other
   CREATEROLE users. Whichever CREATEROLE
   users have ADMIN OPTION on a role at any given time
   can administer it.