Re: Design proposal: fsync absorb linear slider

Hi

On Tue, Jul 23, 2013 at 5:48 AM, Greg Smith <greg(at)2ndquadrant(dot)com> wrote:

> Recently I've been dismissing a lot of suggested changes to checkpoint
> fsync timing without suggesting an alternative. I have a simple one in
> mind that captures the biggest problem I see: that the number of backend
> and checkpoint writes to a file are not connected at all.
>
> We know that a 1GB relation segment can take a really long time to write
> out. That could include up to 128 changed 8K pages, and we allow all of
> them to get dirty before any are forced to disk with fsync.
>
> It was surely already discussed but why isn't postresql writing
sequentially its cache in a temporary file? With storage random speed at
least five to ten time slower it could help a lot.
Thanks

Didier