Radoslav Nedyalkov <rnedyalkov(at)gmail(dot)com> writes:
> We have a busy database that has oid increasing with 50-100M per month.
> There is no oid type across user attributes anywhere nor user tables with
> oids;
> Not sure where this generation comes from. If you can hint me, it would be
> great.
Lots of short-lived temporary tables, maybe?
> Also what happens when pg_class.oid reaches 4B.
Nothing. The counter will wrap around and you won't notice a thing.
regards, tom lane