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.For instance, the qualifier argument corresponds to the
    szTableQualifier and cbTableQualifier arguments of an ODBC catalog
    function.  The SQL NULL value corresponds to the C NULL value.
    The arguments can contain % signs, which are interpreted as in LIKE.