1 table-identifier
2? (
2.1+ ,
2.1 column-name
2.2 )
3 AS ( fullselect
4? order-by-clause
5? fetch-first-clause
6 )
7? search-clause
8? cycle-clause

search-clause:

1 SEARCH
2 DEPTH FIRST
2 BREADTH FIRST
3 BY
4+ ,
4 column-name
5 SET seq-column-name

cycle-clause:

1 CYCLE
2+ ,
2 column-name
3 SET cycle-column-name TO constant DEFAULT constant
4? USING using-column-name