Re: What affects performance?

In article <2svhn3INN3c8_at_news.ougf.fi> rissahe1_at_news.ougf.fi (Heikki Rissanen) writes:
>Bill Miller (turboman_at_teal.csn.org) wrote:
>
>: What hardware parameters have the greatest impact
>: on performance?
>
>I think that most responses are a bit too academic. If we take a little
>more practical approach, we can ask "What do DBA's usually do to increase
>performance?"
>
>And the answer is something like:
>
> 1) Double your hardware, or triple is you can afford.
>
> 2) If it doesn't help, try to figure out what's wrong.
>
>This is not (just) a joke. I've seen this sooo often, especially with third
>party software packages, when it is cheeper to buy hardware than pay the
>specialists to find out where the problem is. And some vendors won't even
>offer changes, because they don't like the idea of supporting a large bunch
>of customised code.
>
>And I expect to see it more often as hardware prices go down and wages don't.
>
>Regards,
> Hessu
>

What Hessu says is minimally true. I was talking to a company today that was addressing the need to install hardware w/ Sybase in 300 branch offices. Doubling or tripling the cost of the hardware obviously is a huge amount of money compared to the fixing inefficencies of the system. Hardware issue that affect performance:

1. The network - at 10M bps, after taking into account overhead and collisions, throughput ranges about the speed of a floppy disk drive. Minimize network traffic!
2. Disks - disk contention is a killer in a database world. many disks are much more important than one or two real big disks.
3. Memory - This is the first hardware to look at to increase when all other optimization avenues have failed. Databases love memory and it is best to feed them alot.

Remember, a poorly contructed SQL statement, or poorly defined index will kill your performance regardless of the amount of hardware.

regards,

Joe Dunn

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>Heikki Rissanen, United Papermills, Rauma, Finland
>Email: heikki.rissanen_at_ra.upm.yhtyneet.mailnet.fi
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Joe Dunn            Hughes Network Systems          jdunn_at_hns.com