Thanks for that answer
"Howard J. Rogers" <hjr_at_dizwell.com> a écrit dans le message de
news:3fa85542$0$9226$afc38c87_at_news.optusnet.com.au...
>
> "Guy Dallaire" <gd-newsgroups_at_spamex.com> wrote in message
> news:1xQpb.641$143.28461_at_news20.bellglobal.com...
> > Say you have 8 disks in a hardware raid controller on which you want to
> > place oracle datafiles. Your redo logs are duplexed on another separate
> pair
> > of disks. You want mirroring
> >
> > What is the best scenario:
> >
> > a) Create 4 mirrors of two disks each, and treat each mirror as separate
> > devices, place indexes and data files on separate disk, juste like on a
> > regular disk.
>
> Is there no end to this madness?
>
> Why physically separate indexes and data files?? Why????
>
> It provides no performance benefit. And you can create separate
tablespaces
> to get the management benefits, and still house both tablespaces on the
same
> array.
>
> In case you're new here, please have a butcher's at google.com for this
> newsgroup over the past year. You will discover a general consensus
> (finally!) that index/table-separation-yields-performance-benefits is just
> another hoary old myth from the Oracle Stables. Long since debunked and
> totally untrue even when being promulgated by The Corporation itself
(which
> its latest doco now no longer does, thank God.)
>
> By the way, I would go (a) or (c), with a preference towards (a). I'd
prefer
> to keep SYSTEM, UNDO and TEMP away from everything else if at all
possible.
> So if I was doing (a), it would be 4 arrays, 1 for SYSTEM, 1 for UNDO, 1
for
> TEMP and 1 for everything else. Regardless of whether it's an index or a
> table.
>
> The only problem with that distribution is that SYSTEM rarely needs to be
> bigger than a couple of hundred meg. Even I, with my shares in Seagate,
have
> a problem recommending an entire 30GB+ RAID array for SYSTEM on its own.
>
> (c) has the advantage of utter simplicity, and such looney space wastage
> issues don't arise. And for the majority of databases out there, the
> performance worries that arise from striping everything together probably
> won't be an issue. Probably. Maybe.
>
>
>
>
> >
> > b) Create 2 stripped mirrors of 4 disks each, one for indexes, one for
> > tables.
> >
> > c) Create 1 big stripped mirror with the 8 disks and place all datafiles
> on
> > it, regardless of types of segments.
> >
> > The RAID Array is a sun storedge 3310 with 2 controllers (512 Mb cache)
> >
> >
> >
> >
> >
> >
>
>
Received on Wed Nov 05 2003 - 08:59:29 CST
