Re: Tablespaces and indexes

Galen Boyer wrote:
>
> On Fri, 21 Sep 2001, nsouto_at_optushome.com.au.nospam wrote:
>
> > As you pointed out, there may be other considerations:
> > similarity of space allocation being one that springs to mind
> > (for dictionary-allocation tablespaces). Or partitioning.
>
> I asked this question as a standalone post but it is relevant
> here. Are there performance gains with partitioning when there
> is striping? I guess with multiple sets of arrays, partitioning
> to a certain array would give performance gains, but if using one
> striped array, I don't see partitioning bringing performance
> gains.
>
> > Fact is: most people nowadays use some form of SAN or other
> > RAID-based architecture or a very good LVM. With these, there
> > is no point whatsoever is spending large amounts of time
> > splitting your database into lots of tablespaces, be they
> > indexes or table or mixed.
>
> Hence my question about partitioning.
>
> > Want more speed for reading? Use mirroring.
>
> Why does this work? I thought mirroring was a second layer of
> safety. Does Oracle use both sides of the mirror based on its
> intelligence?
>
> --
> Galen Boyer
> It seems to me, I remember every single thing I know.

Partitioning has massive benefits over and above IO performance.

• elimination
• parallel dml
• drop/exchange partition (vital in warehouses)
• easier management (smaller objects)

In terms of the mirroring question, you can use your volume mgr to do such things as

• send a read request to both mirrors and use which one comes back fastest
• rotate read requests in round-robin to get sort of a "2-disk stripe" on the mirror (for lack of a better term)

hth
connor

-- 
==============================
Connor McDonald

http://www.oracledba.co.uk

"Some days you're the pigeon, some days you're the statue..."