Re:

Oleg Bartunov <oleg@sai.msu.su> writes:
> btw, is there a restriction to length of key in GiST in 7.1 ?

Index tuples still have to fit in a block --- no TOAST table for
an index (yet).

I think we can compress index datums in-line though; at least that
should work in principle.
        regards, tom lane