Re: Specific questions about wraparound and vacuum

On 8/8/07, Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> wrote:
> "Nick Fankhauser" <nickf(at)doxpop(dot)com> writes:
> > One other question- when I'm vacuuming, I always get the warning:
>
> > WARNING: some databases have not been vacuumed in <big number> transactions
> > HINT: Better vacuum them within <big number> transactions, or you may
> > have a wraparound failure.
>
> > I get these even after all DBs except template0 have been freshly vacuumed. Why?
>
> Do your vacuums change the pg_database.datfrozenxid values for the
> databases? The only reason I can think of for them not to do so
> is if you're not doing them as superuser ...
>
> regards, tom lane
>

They do change the values- I noted this by selecting age(datfrozenxid)
in template1 both before and after vacuuming and noting the change.
Also, the maintenance process that does the regular vacuum on our
"prod" database is run as user postgres.

Our regular vacuum process only runs on our single "prod" database-
not template1. Is template1 a "frozen" database, or just template0? If
template1 is not frozen, that may explain the warning. Would I get the
warning even if the DB that has not been recently vacuumed has never
had any transactions on it?

-Nick

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