Re: What affects performance?

In article <2svhn3INN3c8@news.ougf.fi> rissahe1@news.ougf.fi (Heikki Rissanen) writes: >Bill Miller (turboman@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 >-- >--------------------------------------------------------------------- >Heikki Rissanen, United Papermills, Rauma, Finland >Email: heikki.rissanen@ra.upm.yhtyneet.mailnet.fi >--------------------------------------------------------------------- -- ----------------------------------------------------------------- Joe Dunn Hughes Network Systems jdunn@hns.com