The DELETE FILE_ELEMENT command deletes a file element and,
    optionally, all children of the file element to the bottom of
    the collection hierarchy.

    Because a file element is a controlled element, CDO freezes
    all previous versions and allows you to delete only the highest
    visible version.

    CDO cannot delete the following versions in a branch line:

    o  A version that is owned by a version in a different branch

    o  A version that owns an intermediate version in a different
       branch

    See the Oracle CDD/Repository Architecture Manual for information
    on branch lines of descent.