Re: Bgwriter LRU cleaning: we've been going at this all wrong

On Tue, 26 Jun 2007, Heikki Linnakangas wrote:

> I haven't worked on [Greg's] patch. I started looking at this, using 
> Itagaki's patch as the basis.

The main focus of how I reworked things was to integrate the whole thing 
into the pg_stat_bgwriter mechanism.  I thought that made the performance 
testing a lot easier to quantify; the original patch pushed out debug info 
into the logs which wasn't as helpful to me.  I didn't do much with the 
actual approach, my version was still following Itagki's basic insight 
into the problem.  I did change the smoothing method some, but as you say 
that's up for grabs anyway.

> Since you have the test environment ready, can you try alternative 
> patches as well as they're proposed?

The real upper limit on how much testing I can do is my home server's 
capabilities, which for example aren't robust enough disk-wise to run 
things like DBT2 on the scale I know you normally work on.  I gots a disk 
for the database, one for the WAL, 256MB of cache on the controller, and a 
single dual-core procesor; can't fit too many warehouses here.

--
* Greg Smith gsmith@gregsmith.com http://www.gregsmith.com Baltimore, MD