On Thu, 2003-03-13 at 04:28, scott.marlowe wrote:
> On Wed, 12 Mar 2003, Stefan Sturm wrote:
>
> > Hello,
> >
> > we have a performance problem with PostgreSQL 7.2.4. But first I try to
> > explain our situation:
> >
> > We have an online game. This game is a fantasy game, where you can buy
> > and sell players for your team.
> > All players for the teams are stored in one table. So in this table we
> > have just one primary key and to foreign keys.
> > When we have around 500 Users at one time on the maschine, the game is
> > slowing down(Time for one spage up to 1minute and more). And I think
> > the problem is this table. There are a lot of reading and writing
> > connections to this table.
> >
> > So now my question: What can I do to increase the performance?
>
> Hi Stefan, the first step to increasing performance is surveying the
> current situation. When the machine starts to slow down, what does the
> output of top look like? Is the machine running out of any resources like
> file handles or memory? Note that most flavors of unix will not show a
> lot of memory free they will show it being used as cache. If your machine
> shows 400 megs of system cache and postgresql is using 4 megs of shared
> memory, you aren't giving enough to postgresql. It'll go slow.
To add to what Scott says, what does vmstat report (are you swapping?).
If you're not already, install sar and see how much I/O and CPU you're
consuming - one important issue is whether you're running out of I/O
capacity or CPU or RAM.
Stephen
