Greg Smith wrote:
> Here are some more recent papers that also give good insight into
> research in this area:
>
> http://www.cs.usask.ca/~wew036/comprehensive.pdf
> http://www.cse.ohio-state.edu/hpcs/WWW/HTML/publications/papers/TR-05-3.pdf
Nice papers.
What I'd like to see is a paper on precleaning strategies. I tried to
google for one but couldn't find any. That would be very relevant to the
bgwriter tuning discussions.
I'm still struggling to understand why and how bgwriter increases
performance. Under what circumstances, what workload?
The only benefit I can see is that it moves the write() of a page out of
the critical path. But as long as the OS cache can absorb the write, it
should be very cheap compared to doing real I/O. Apparently the workload
that benefits most is an OLTP workload where response times are
critical, on a database that doesn't fit in share_buffers, but fits in
OS cache.
Am I missing something? What kind of a test would show the most benefit?
-- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com