sum on tree structure

[TomazZ]

If you have Oracle 8.1.6 or above then you can use the following form of subquery:

select title,
(select sum(num) from ogcostt
connect by prior srl=ogcost_srl
start with srl=a.srl)
from ogcostt a;

I don't think, though, that it is much more efficient. Try.
Hope it helps.

Tomaž