Re: Scalable Performace - Inserts/Updates

In article <977519319.7059.0.nnrp-13.9e984b29_at_news.demon.co.uk>,   "Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote:
>
> Is it the performance or the safety you worry about ?

Haven't seen any real requirements defined for either, now that you mention it.

>
> Yes, the SAN on a fibre can be faster than a local
> disk, especially since SANs tend to come complete
> with battery backed buffers.
>
> Yes, the SAN is as safe as the local disk (it must
> be or you wouldn't be able to run any Oracle data
> file on it at all).

Well, why couldn't you run Oracle on an unsafe disk? At least, until it actually does something wrong!

To split some obvious hairs: Battery backup has nothing to do with transfer rate (excepting 0 rate with no power of course). Oracle doesn't care how safe a disk is unless it is actually not working, and may even not care then if the device is only ocassionally spewing garbage.

Now, you must understand my guts. I have personally seen the effects of people shutting off all power (backup and line), miswired UPS exploding, generator power fed into line power, failsafe disk software failing due to hardware problems, incorrect backup procedures, bugs in Oracle doing all sorts of weird things, earthquakes and floods. And I'm just a database guy! On top of that, I'm a long time comp.risks fan. Sometimes I wonder why I don't just crawl into the closet... well, no I don't, I'd probably die from the fire from the voltage surge into my smoke detector after a line transformer explodes and everyones unrectified y2k generator pops online...

Now this SANS has the (to me) unique feature of working with different types of hardware. One part of it looks like a Sun, one part looks like an HP, one part looks like an NT... I have trouble mentally assimilating such complete partitioning dynamically without bugs. And my gut still has a bit of difficulty with the idea that moving data from there to here is faster than moving data from here to here! :-)

>
> --
> Jonathan Lewis
> Yet another Oracle-related web site: http://www.jlcomp.demon.co.uk
>
> Practical Oracle 8i: Building Efficient Databases
>
> Publishers: Addison-Wesley
> See a first review at:
> http://www.ixora.com.au/resources/index.htm#practical_8i
> More reviews at: http://www.jlcomp.demon.co.uk/book_rev.html
>
> Joel Garry wrote in message <920ap7$o2e$1_at_nnrp1.deja.com>...
>
> >I won't. I've got a situation which works ok now, but eventually
 will
> >scale. I have the redo logs on the local disks. However, the data
> >files are on a humungo SANS. The thing that is strange - the SANS
 is
> >over fibre, and is quite a bit faster than the local disks. So
 should
> >I move them there? My head says yes, my gut says "huh? Network
> >faster than local disk?"
> >
> >An Oracle Corp contractor DBA using another hardware platform to the
> >same SANS couldn't be convinced to do it, is the only reason I
 haven't.
> >Hitachi's uptime guarantee on the SANS is better than the service
> >agreements with the unix vendors...
> >
>
>

--
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