Re: ACM Paper relevant to our buffer algorithm

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