Although the I/O requests for a single row lookup are separate and therefore
not technically concurrent, I still prefer to keep indexes and the data they
refer to on different spindles. It won't make that much difference for a
single user doing one fetch, but can make a big difference when lots of
users are doing it at the same time. Even when those I/Os are mixed with
different I/O requests from other sessions, I like to give the OS, the HBAs
and the disk array every opportunity to parallelize I/O. Even with RAID
where the data and indexes are striped, keeping the data and indexes on
different RAID groups on separate sets of spindles can dramatically improve
I/O throughput in high concurrency environments.
John Smiley
Technical Management Consultant
TUSC, Inc.
On 6/19/05, Jared Still <jkstill_at_gmail.com> wrote:
>
> Hi Raj,
>
> I think it might be more accurate to say somthing list this:
>
> "It is not required to separate table and index I/O".
>
> The issue was really IO, and separating indexes and tables
> based on the mistaken idea that the table/index IO was concurrent
> on a single row lookup is a myth of longstanding.
> ( I fell for it once upon a time )
>
> Separating indexes and tables at a logical level has some management
> benefits as other posters have stated.
>
> Jared
>
>
> On 6/15/05, rjamya <rjamya_at_gmail.com> wrote:
> >
> > since the new (it isn't really new but still) wisdom says "it is not
> > required to separate tables and indexes in different tablespaces", this
> > whole issue becomes a moot point. I don't see any logic in being able to
> >
> > specify default index tablespace.
> > if so then can I specify default tablespace for lobs? iots? o.h and I
> > need
> > separate tablespaces for pks and fks as well.
> >
> > Raj
> >
> > On 6/15/05, Mladen Gogala < mgogala_at_allegientsystems.com> wrote:
> > >
> > > John Dunn wrote:
> > >
> > > >When I create a user is it possible to specify a default tablespace
> > for
> > > >indexes that is different from the default tablespace for tables?. Or
> > can
> > > I
> > > >only specify a different tablespace for indexes when I create the
> > index?
> > > >
> > > >This is Oracle 9.2
> > > >
> > >
> >
> > --
> > http://www.freelists.org/webpage/oracle-l
> >
>
>
>
> --
> Jared Still
> Certifiable Oracle DBA and Part Time Perl Evangelist
>
>
--
http://www.freelists.org/webpage/oracle-l
Received on Mon Jun 20 2005 - 13:49:41 CDT
