> Hello, > > Shridhar Daithankar and Josh Berkus write on > http://www.varlena.com/varlena/GeneralBits/Tidbits/perf.html > > shared_memory > > """ > There is one way to decide what is best for you. Set a high > value of this parameter and run the database for typical > usage. Watch usage of shared memory using ipcs or similar > tools. A recommended figure would be between 1.2 to 2 times > peak shared memory usage. > """ > > I tried to find a way to do this on windows. Scanning all the > lines of perfmon memory options, I could not see anithing > like "shared memory usage". > > Googling for "shared memory usage" just drove me to some > ancient WRONG information that PostgreSQL is not possible on > Windows because of lacking shared memory. (guess that was for > Windows 95 or similiar) > > So: has anybody a hint how I can check how much shared_memory > is really used by PostgreSQL on Windows, to fine tune this parameter? > > I learned the hard way that just rising it can lead to a hard > performance loss :) Not really sure :) We're talking about anonymous mapped memory, and I don't think perfmon lets you look at that. However, there is no limit to it as there often is on Unix - you can map up to whatever the virual RAM size is (2Gb/3Gb dependingo n what boot flag you use, IIRC). You can monitor it as a part of the total memory useage on the server, but there's no way to automatically show the difference between them. //Magnus
