Betsy Barker <betsy(dot)barker(at)supportservicesinc(dot)com> writes:
> I am using PostgreSQL 7.3.4 and have noticed something odd while using
> a sequence. After using 3000 values, I seem to be getting a duplicate.
I don't think I'm going to believe that without seeing a complete test
case. It seems much more likely that there's a bug in your program.
The cache_value setting of 1000 seems awfully high; that would very
likely cause odd behavior in terms of values being skipped or not being
handed out in sequence. But I've not heard of any problems that could
cause generation of duplicates (at least not since 7.2.1, and even that
bug only surfaced during a database crash).
regards, tom lane