Only one page of one area is accessible to RdbALTER at a time.
    This command switches you from one page of the currently attached
    database to another page.

    When you attach to a database, RdbALTER automatically makes area
    1 the current area and page 1 of that area the current page. To
    work on any other area and page, you must use the AREA . . . PAGE
    command.

    If you specify AREA but not PAGE, RdbALTER makes the area you
    specify current and fetches page 1 of that area.

    If you specify both AREA and PAGE, RdbALTER makes the area you
    specify current and fetches the page you specify from the new
    current area.

    If you specify an area or page that does not exist, an error
    occurs and the current area and page do not change.

    Use the PAGE option to switch from one page in the current area
    to another page in the current area.