Re: [Patch] Checksums for SLRU files

Hi,

On 2018-08-01 10:58:03 -0700, Shawn Debnath wrote:
> On Wed, Aug 01, 2018 at 02:06:44PM +0300, Andrey Borodin wrote:
> > But adding LSNs, and whole regular PageHeader is quite easy in this
> > patch. Do you think we should really go that way?
> >
> > Putting SLRUs into usual shared buffers and WAL-logging looks like a good idea, but a lot of work.
>
> Back at PgCon in Ottawa this year, I pitched the idea to moving
> components off of SLRU and on to the buffer cache.

I believe you also planned to work on that, do I remember that
correctly, or is that just wishful thinking?

> That idea would
> involve adding regular page headers to SLRU blocks, and transitioning
> various components like multixact, commit timestamp, clog, subtrans and
> others, to being first class residents in the buffer cache. The goal is
> to provide performance benefits along with resiliency.
>
> I believe Heikki also mentioned wanting support for stamping LSNs to
> ensure durability in clog. I agree with the idea of incorporating the
> PageHeader at the beginning of the SLRU page to maintain checksums and
> we can iteratively add support for tracking LSNs if necessary.

I'm entirely in agreement with that goal, for the reasons stated above.

Greetings,

Andres Freund