I'm having the same problem here.
I've got two identical tables of which one is a remote db. They both have over 6 million records, but on doing count(*) on these table, there is a difference of 140 rows. So, I'm trying to find the rows using select col1,col2,col4,col5 from db1
minus
select col1,col2,col4,col5 from db2@remotesite

but this is taking ages. I started the run at 9.19 and it's 10.02 now and havent got any results yet. Is there any way I can speed this up. I'm using oracle 9.0.1.3.0. Any help would be very much appreciated.

Thanks a lot