Fred Moyer wrote:
> Your UDMA 33 bus will limit disk reads to 33 Mbytes/sec so there is your
> first bottleneck. Get a 66 mhz PCI ide adapter (Promise is cheap) and that
> will increase your disk speed dramatically.
> Also you won't be able to do much with 128 Mb of ram, put in as much as you
> can. That box is likely 66 mhz front side bus so that will be a bottleneck
> once you max out the ram.
>
[snip]
>
>>Resently I had to create and manage the (relatively) large table.
>>In the mean time it's about 8 million rows, and surely will grow above
>>this size.
>>The problem is that queries takes absolutely not acceptable time.
>>Database located on average Celeron 400 machine with 128 Mb of RAM and
>>UDMA 33 capable IDE drive.
>>I run PostgreSQL 7.1 on Debian Linux with 2.4.18 kernel.
>>My question is what could be done in order to improve the performance?
>>I mean, is that normal behavior for Postgres on such computer or I
>>encounter a misconfiguration?
Also, the Celeron processor is cache-starved. If you can switch it out
for a P3 at even the same clock speed, it'd be worth it. A while back,
someone posted benchmarks where he just changed the processor from a
Celeron to a P3 of the same clock speed and the P3 was twice as fast.
Databases are I/O bound. Anything you can stuff into cache is worth it.
This is why lots of memory, big disk caches, disk controller caches, and
processor caches help so much.
--Jeremy
