Re: patch to allow disable of WAL recycling

At Thu, 19 Jul 2018 12:59:26 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote in <20180719(dot)125926(dot)257896670(dot)horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>
> At Thu, 19 Jul 2018 12:37:26 +0900 (Tokyo Standard Time), Kyotaro HORIGUCHI <horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp> wrote in <20180719(dot)123726(dot)00899102(dot)horiguchi(dot)kyotaro(at)lab(dot)ntt(dot)co(dot)jp>
> > At Tue, 17 Jul 2018 21:01:03 -0400, Robert Haas <robertmhaas(at)gmail(dot)com> wrote in <CA+Tgmob0hs=eZ7RquTLzYUwAuHtgORvPxjNXgifZ04he-JK7Rw(at)mail(dot)gmail(dot)com>
> > > On Tue, Jul 17, 2018 at 3:12 PM, Peter Eisentraut
> > > <peter(dot)eisentraut(at)2ndquadrant(dot)com> wrote:
> > > > The actual implementation could use another round of consideration. I
> > > > wonder how this should interact with min_wal_size. Wouldn't
> > > > min_wal_size = 0 already do what we need (if you could set it to 0,
> > > > which is currently not possible)?
> > >
> > > Hmm, would that actually disable recycling, or just make it happen only rarely?
> >
> > It doens't. Instead setting max_wal_size smaller than checkpoint
> > interval should do that.
>
> And that's wrong. It makes checkpoint unreasonably frequent.
>
> My result is that we cannot disable recycling perfectly just by
> setting min/max_wal_size.

s/result/conclusion/;

regards.

--
Kyotaro Horiguchi
NTT Open Source Software Center