Re: [Patch] Checksums for SLRU files - Mailing list pgsql-hackers

From Andres Freund
Subject Re: [Patch] Checksums for SLRU files
Date
Msg-id 20180801180046.qkv6drrl6f6qzrsi@alap3.anarazel.de
Whole thread Raw
In response to Re: [Patch] Checksums for SLRU files  (Shawn Debnath <sdn@amazon.com>)
Responses Re: [Patch] Checksums for SLRU files
List pgsql-hackers
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


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