"Thilina Gunasekara" <tgunasekara@openworld.org> writes:
> **** This is Box A which runs on 7.4.5 and delivers very quick result.
> ...
> ****** And this is the Box B which runs on 7.3.9 and takes hours to deliver
> the result.
Well, that's what I'd expect. There's a reason why we put a great deal
of effort into fixing IN in 7.4 ;-)
regards, tom lane