Identifies the database root file associated with the database.
    If you specify a repository path name, the path name indirectly
    specifies the database root file. The ALTER DATABASE statement
    does not change any definitions in the repository, so there is no
    difference in the effect of the PATHNAME and FILENAME arguments.

    If the database referred to in the PATHNAME or FILENAME argument
    has been attached, the ALTER DATABASE statement will fail with a
    file access conflict error.