Re: Final background writer cleanup for 8.3

On Fri, 24 Aug 2007, Tom Lane wrote:

> Heikki makes a good point nearby that if you are not disk write
> bottlenecked then it's perfectly OK for backends to issue writes, as
> it'll just result in a transfer to kernel cache space, and no actual
> wait for I/O. And if you *are* write-bottlenecked, then the last thing
> you want is any wasted writes.

Which is the same thing I was saying in my last message, so I'm content
we're all on the same page here now--and that the contents of that page
are now clear in the archives for when this comes up again.

> So a fairly conservative strategy that does bgwrites only "just in time"
> seems like what we need to aim at.

And that's exactly what I've been building. Feedback and general feeling
that I'm doing the right thing appreciated, am returning to the code with
scaling factor as a new tunable but plan otherwise unchanged.

--
* Greg Smith gsmith(at)gregsmith(dot)com http://www.gregsmith.com Baltimore, MD