embedded select

my question concerns doing and embedded select statement inside another select (don't know what the term for it is). Something like

select x, (select a from b where b.x = z.x) from z
;

Now, this works fine for me in 8i and above, but not in 8.0.5. What I'd like to know is if this is something new to 8i, and if so, is there any kind of "add-on" or anything I can do to an 8.0.5 to make it work there as well?

--
Luch
replace nospam with hotmail for e-mail.