AddingandDeletingPostgres Users
          Note that commands preceeded by a ’* ’ are to be executed from the Postgres terminal monitor,
        while those preceeded by a ’% ’ are to be executed from a C shell. Unless stated otherwise, shell com-
        mandsworkfromanyshell.
        1. Adding
          ADBAmayaddaPostgresuserbyissuingthefollowingcommands.
            * append pg_user (usename=<username>, usesysid=<userid>)
          where username is the user name from /etc/passwd, and userid is the user number or id from
        /etc/passwd. The usesysid number does not have to be identical to that in /etc/passwd, but the username
        has to exist on the machine that the user will run Postgres applications from (not necessarily on the
        Postgres server).
          In older versions of Postgres, you may have to do the following:
            * append pg_user (usename="<username"::char16, usesysid="<userid>"::int2)
          This procedure will create a Postgres user, but will not create any databases for that user - they must
        do this for themselves using the "createdb" command.
        2. Deleting
          Postgres users may be deleted through the following mechanism:
        2.1. Determine
          Determine which databases are owned by that user by running the following query
            * retrieve (pg_database.all) where pg_database.datdba = "<userid>"::oid
        2.2. Destroy
          Destroy those databases owned by that user using the "destroydb" command. You may want to make
        this a shell script.
            %foreach i (<databases>)
            ? destroydb $i
            ? end
        2.3. Delete
          Runningthe following query will delete that user from pg_database.
            * delete pg_user where pg_user.usesysid
        3. ADDITIONAL
        3.1. Superuser
          The superuser (root) or any other user with userid zero should not be a Postgres user - this will cause
        various problems. The DBA should be user "postgres".