Re: Large database help

On Sun, Apr 22, 2001 at 05:12:20PM -0400, xbdelacour(at)yahoo(dot)com wrote:
> My problem is this: during the query process the hard drive is being tagged
> excessively, while the cpu's are idling at 50% (numbers from Linux command:
> top), and this is bringing down the speed pretty dramatically since the
> process is waiting on the hard disk. How do I get the database to be
> completely resident in memory such that selects don't cause hdd activity?
> How do I pin how exactly why the hard disk is being accessed?

50% idle on a 2 CPU system mean one CPU is busy and one is idle - as
expected if you run a single CPU-intensive job.

> I am setting 'echo 402653184 >/proc/sys/kernel/shmmax', which is being
> reflected in top. I also specify '-B 48000' when starting postmaster. My
> test DB is only 86MB, so in theory the disk has no business being active
> once the data is read into memory unless I perform a write operation.. What
> am I missing?

What does top say?
How much memory do each of your postgres processes take, and how much of
it is shared?
Is there any free memory?

--
Ragnar Kjørstad