Jeff <threshar@torgo.978.org> writes:
> given that template0 and 1 rarely change.. I don't see why we'd need to
> vacuum them
You have to vacuum template1 periodically if you want pg_clog to shrink.
You may know that you've never changed it, but the VACUUM code doesn't
know that.
template0 need not get vacuumed as long as it's marked datallowconn = false
in pg_database. VACUUM assumes it's not been changed if that flag is
present.
regards, tom lane