Re: patch to allow disable of WAL recycling

Alvaro,

I'll perform several test runs with various combinations and post the
results.

Thanks,
Jerry


On Tue, Jul 10, 2018 at 2:34 PM, Alvaro Herrera <alvherre@2ndquadrant.com>
wrote:

> On 2018-Jul-10, Jerry Jelinek wrote:
>
> > 2) Disabling WAL recycling reduces reliability, even on COW filesystems.
>
> I think the problem here is that WAL recycling in normal filesystems
> helps protect the case where filesystem gets full.  If you remove it,
> that protection goes out the window.  You can claim that people needs to
> make sure to have available disk space, but this does become a problem
> in practice.  I think the thing to do is verify what happens with
> recycling off when the disk gets full; is it possible to recover
> afterwards?  Is there any corrupt data?  What happens if the disk gets
> full just as the new WAL file is being created -- is there a Postgres
> PANIC or something?  As I understand, with recycling on it is easy (?)
> to recover, there is no PANIC crash, and no data corruption results.
>
> --
> Álvaro Herrera                https://www.2ndQuadrant.com/
> PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services
>