Re: [HACKERS] Checksums by default?

On 2017-01-26 09:19:28 +0900, Michael Paquier wrote:
> On Thu, Jan 26, 2017 at 9:14 AM, Peter Geoghegan <pg@heroku.com> wrote:
> > On Wed, Jan 25, 2017 at 3:30 PM, Stephen Frost <sfrost@snowman.net> wrote:
> >> As it is, there are backup solutions which *do* check the checksum when
> >> backing up PG.  This is no longer, thankfully, some hypothetical thing,
> >> but something which really exists and will hopefully keep users from
> >> losing data.
> >
> > Wouldn't that have issues with torn pages?
> 
> Why? What do you foresee here? I would think such backup solutions are
> careful enough to ensure correctly the durability of pages so as they
> are not partially written.

That means you have to replay enough WAL to get into a consistent
state...

- Andres