Re: Automatic Undo Managment on 9i

"Niall Litchfield" <n-litchfield_at_audit-commission.gov.uk> wrote in message news:3e01903f$0$248$ed9e5944_at_reading.news.pipex.net...
> "Timmy Sin" <tswsin_at_yahoo.com> wrote in message
> news:ats1in$h0u$1_at_news.hk.linkage.net...
> > Thanks Howard and Daniel.
> >
> > So, I can just create a single undo tablespace, enable it to be
AUTOEXTEND
> > and no more administration and sizing is required.
>
> Yes you can just create a single undo tablespace, I think I'd recommend
this
> though you might wish to stripe it across several disks for performance.
I'm
> not a big fan of autoextend (and certainly not without maxsize set)
> especially for UNDO as this would be a good way to fill a disk
unexpectedly.
> It is also not true that NO administration and sizing is required, just
> less. You don't have to worry about how many rollback segments and what
size
> they should be, you do need to worry about the undo retention period and
how
> much undo space you need.

Hi Niall,

Totally agree ...

> >
> > How about the feature "local management tablespace" already available in
> 8i?
> > Are you using them or the dictionary management tablespace?
>
> I can think of almost no downsides to use of LMT's, and a whole host of
> advantages especially if you do the sensible thing and go for a uniform
> extent size. As of 9.2 even the system tablespace is locally managed which
> should tell you something.

I can think of one downside. The fact you can't specify maxextents.

IMHO, a potential pain in the butt and one for which I've heard no sound reason.

Picky ain't I :)

Richard Received on Thu Dec 19 2002 - 04:44:06 CST