"Gaetano Mendola" <mendola@bigfoot.com> writes:
> How is it possible have the oid and the id_user_traffic (
> serial primary key ) duplicated ? Any idea ?
Have you had any power failures lately? Tried to copy a running
database via "tar" or "cp"? Anything interesting like that?
There are ways for multiple versions of a row to all appear good,
if something happens that breaks the synchronization between datafiles
and pg_clog. AFAIK these all reduce to DBA error (copying a live
database) or hardware misfeasance (disk drive claiming write complete
before it really is, and then losing the data in a power failure).
Also, what Postgres version are you using? Awhile back there was a bug
that allowed a sequence to appear to go backward in a crash.
regards, tom lane