Re: Two sanity checks

Niall Litchfield doodled thusly:

>> second one is on system indentifier which is varchar2(256). Looks to
>> me like a pretty crappy design and performance will be terrible.

Yup. Definitely!

>for this purpose to me. I'd be prepared to bet as well that as the users of
>the system discover what the performance is like on this audit table the
>'need' for extensive auditing magically evaporates.

which probably is not a bad idea, come to think of it? <d&r>

>> That sounds to me like (sorry for that word) a bullshit, because disk
>> I/O is still very slow (comparing to memory, interfaces etc.) and
>> having everything in one big mess can't bring the same performance as
>> properly distributed files (OFSA) even with help of all stripes and
>> caches in the universe.
>
>Again I agree. Certainly when we looked at a SAN environment you still ended
>up with raid volumes (albeit managed in whizzy new ways on a clever
>infrastructure). I'd also want to be sure that you still got a guranteed
>write when you requested one and what difference if any that makes to
>performance.
>>

hmmm! mixed feelings on this one, folks. To me the OFA/OFSA value was always in providing a structured way to implement the Oracle database software and facilitate its maintenance and tuning. Ie, not the REASON for increased efficiency, but as a facilitator of such.

Use the fastest SAN/whatever you can find with an ad-hoc software and DB install and problems will surely follow, no matter what. Follow OFA and things become so easy it's not even worth weighing in performance comparisons: bleeding obvious. However, the same applies to normal disks/controllers.

As for the value of SAN caches: give me an EMC configured with large partitioned caches and let me plonk OFA into that and I'll show you a DB running with truly unreal I/O rates, whatever the user load. They really can be very good!

Traditional I/O configs are very flexible and let us do all sorts of trickery for performance. But they are also tremendous time wasters if we're not careful to draw a line in the sand. The SAN things with their "you-beaut" caches are absolutely superb and save a LOT of time in fiddling about with disk/controller mixes.

However, without minimal preparation in terms of file system distribution a-la OFA, they really cannot provide max throughput of themselves.

If given the choice I'll always take the SAN: re-configuring the darn things is soooooo much easier than fiddling around with controllers, disks, LVMs and such, it's not even worth comparing! However, they can be quite expen$$$ive.

So really: 6 of one, half a dozen of the other.

>
>It is worth bearing in mind though that some consultants are worth their
>weight in gold.
>

is that a veiled reference to the girth of some of them? lol!

Cheers
Nuno Souto
nsouto_at_optushome.com.au.nospam Received on Thu Feb 07 2002 - 08:21:54 CST