Thank you for your answer! *"You did not give CPU and disk info. But still 57 seems a small number. What I guess is you're running pgbench with scale factor 1 (since you haven't mentioned scale factor) and that causes extreme contention for smaller tables with large number of clients."*
My CPU is 2CPU: Intel(R) Xeon(TM) CPU 3.20GHz. Disk: disk system is RAID-5; OS CentOS. the number of scale in pgbench initialization is 100. It will be generate 10 000 000 rows in the accounts table. Fill factor is default. In the other way, I heard that: PostgreSQL working with RAID-10 better than RAID-5 is it right? * "Regarding maximum number of clients, check your "max_connections" setting." * I set max_connections is 200. * * 57 seems a small number, according to you, how much tps is normal or fast? and what is the different of "shared_buffers" and "effective_cache_size". Thank you once more! Regards, Semi Noob 2008/5/15 Pavan Deolasee <[EMAIL PROTECTED]>: > On Tue, May 13, 2008 at 2:43 PM, Semi Noob <[EMAIL PROTECTED]> wrote: > > But after upgrade the max clients is > > also 64 (?!?) Is this the maximum clients support by program pgbench (my > > server on Linux ver8.2.5, pgbench on Windows - version postgresql is > 8.3.1)? > > And the number 57 tps is fast? > > > > You did not give CPU and disk info. But still 57 seems a small number. > What I guess is you're running pgbench with scale factor 1 (since you > haven't mentioned scale factor) and that causes extreme contention for > smaller tables with large number of clients. > > Regarding maximum number of clients, check your "max_connections" setting. > > > Another questions, i heard that PostgreSQL does not support HT > Technology, > > is it right? > > > > I'm not sure what do you mean by HT, but if it's hyper threading, then > IMO that statement is not completely true. Postgres is not > multi-threaded, so a single process (or connection) may not be able to > use all the CPUs, but as long as there are multiple connections (each > connection corresponds to one backend process), as many CPUs will be > used. > > > Last question, i don't understand so much the shmmax, shared_buffers, > after > > upgrading my server from 4 GB RAM to 8 GB RAM, first i configure shmmax > to > > 2GB, share_buffers to 1GB and start server, it runs, after that i set > shmmax > > to 4GB and restart, it fails (?!?). The error logs said that not enough > > share memory! and final i set shmmax to 3GB and share buffer to 2GB, it > > runs. Don't know why, can you explain? > > That doesn't make sense. I am guessing that you are running a 32 bit > OS. 4GB of shmmax won't work on a 32 bit OS. > > Thanks, > Pavan > > Pavan Deolasee > EnterpriseDB http://www.enterprisedb.com >
