Re: Locally Managed vs Dictionary managed tablespaces

Really?!

Since its the extent allocation and de-allocation issues that they are particularly good at, and since rbs's are forever acquiring and dropping extents (or are at risk of the same), TEMP and RBS is where I recommend them the most.

Hate to think I've dropped people in it as a result -got any specific bugs in mind?

Regards
HJR

--

Oracle Resources : http://www.geocities.com/howardjr2000
========================================


"Connor McDonald" <connor_mcdonald_at_yahoo.com> wrote in message
news:3BE19C41.283_at_yahoo.com...


> Niall Litchfield wrote:

> >

> > "Howard J. Rogers" <howardjr_at_www.com> wrote in message

> > news:3be0fd1c$0$9820$afc38c87_at_news.optusnet.com.au...

> > > I have to say that Steve's answer where he says "I would have a

preference


> > > for dictionary management for any tablespace with a large number of

mostly


> > > small constant sized segments" rather begs the question -how do you

ensure


> > > that the segments *are* 'constantly sized'?  Well, using locally

managed


> > > tablespace is the only solution that actually guarantees that!

> >

> > My reading of Steves answer was that he had a preference for dictionary

> > management where the segments were lookup tables and their ilk. i.e they

> > don't grow *by design*. This of course means , as so often, one has to

> > actually understand the data you are looking after.  In this situation I

can


> > go along with the recommendation - though whether I'd actually be

bothered


> > in practice is a moot point. LMT's are great because they avoid

> > fragmentation caused by different sized extents. If your table isn't

growing


> > it won't fragment. In addition I suspect that most such tables should be

> > allocated to a keep buffer pool anyway so physical io wouldn't be a big

> > issue. However having said all that Steve then gives SYSTEM as an

example of


> > such a tablespace and it doesn't fit my reading of the above at all. Of

> > course the best reason of all for making SYSTEM dictionary managed is

that


> > you have to!

> >

> > --

> > Niall Litchfield

> > Oracle DBA

> > Audit Commission Uk

>


> There is still a reasonable argument for making rollback tspaces

> dictionary based - only because of some existing bugs in most of the

> 8.1.x releases.  Other than that, I think lmt's are the canine's

> testicles.

>


> Cheers

> Connor

> --

> ==============================

> Connor McDonald

>


> http://www.oracledba.co.uk

>


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