This function corresponds to the ODBC catalog call of similar name.
    It and related functions are used by the virtual database to query
    remote data dictionaries.The dsn argument must refer to a dsn previously defined by
    vd_remote_data_source or ATTACH TABLE.The qualifier argument corresponds to the szTableQualifier and
    cbTableQualifier arguments of an ODBC catalog function.  A SQL NULL value
    corresponds to the C NULL value.  The arguments can contain % signs, which
    are interpreted as in LIKE.