Re: widen vacuum buffer counters

On Fri, Jan 31, 2020 at 9:59 PM Alvaro Herrera <alvherre@2ndquadrant.com> wrote:
>
> We recently noticed that vacuum buffer counters wraparound in extreme
> cases, with ridiculous results.  Example:
>
> 2020-01-06 16:38:38.010 EST [45625-1] app= LOG:  automatic vacuum of table "somtab.sf.foobar": index scans: 17
>         pages: 0 removed, 207650641 remain, 0 skipped due to pins, 13419403 skipped frozen
>         tuples: 141265419 removed, 3186614627 remain, 87783760 are dead but not yet removable
>         buffer usage: -2022059267 hits, -17141881 misses, 1252507767 dirtied
>         avg read rate: -0.043 MB/s, avg write rate: 3.146 MB/s
>         system usage: CPU 107819.92s/2932957.75u sec elapsed 3110498.10 sec
>
> That's to be expected, as tables exist that are large enough for 4 billion
> buffer accesses to be a possibility.  Let's widen the counters, as in the
> attached patch.
>
> I propose to backpatch this.

+1, and patch LGTM.