Re: Page Checksums

On Mon, Dec 19, 2011 at 8:18 PM, Heikki Linnakangas
<heikki.linnakangas@enterprisedb.com> wrote:

> Double-writes would be a useful option also to reduce the size of WAL that
> needs to be shipped in replication.
>
> Or you could just use a filesystem that does CRCs...

Double writes would reduce the size of WAL and we discussed many times
we want that.

Using a filesystem that does CRCs is basically saying "let the
filesystem cope". If that is an option, why not just turn full page
writes off and let the filesystem cope?

Do we really need double writes or even checksums in Postgres? What
use case are we covering that isn't covered by using the right
filesystem for the job? Or is that the problem? Are we implementing a
feature we needed 5 years ago but don't need now? Yes, other databases
have some of these features, but do we need them? Do we still need
them now?

Tell me we really need some or all of this and I will do my best to
make it happen.

--
 Simon Riggs                   http://www.2ndQuadrant.com/
 PostgreSQL Development, 24x7 Support, Training & Services