Re: Locally managed tablespaces and migrated rows

"Nuno Souto" <nsouto_at_nsw.bigpond.net.au.nospam> wrote in message news:3af7b8a4.4414731_at_news-server...
> Let me reply not only to you here but also to the others that kindly
> participated.
>
> My problem is not with LMTS per se. My problem is that ORACLE
> education (at least here in Oz) is passing on the message (intentional
> or accidentally) that DBAs should use UNIFORM and LMTS for ALL
> tablespaces other than SYSTEM. Across the board. No qualification.

I couldn't say exactly what Oracle Education do say, but i do recall from my own experience that i took in maybe 50% of what was said on the course. (and actually thats a pretty good recommendation for a course IMO - most of them hover around the 25% mark - maybe i'm just a bad learner). unfortunately i took in about another 10-15% that was a) just plain wrong and b) not actually anywhere in the course material so probably not in fact said at all. I'm not sure how you avoid this sort of error - though Howard and others that teach might have suggestions.

> Case in point: with dictionary managed if I decide to have say, 6000
> tables with initial 16K and next 16K, I can. They're mostly empty,
> why make them larger? And the remaining 1000 tables that have any
> real data with corresponding sensible allocations (say 100K/100K,
> 1M/1M, 10M/10M). And I can move these around between the fixed
> tablespaces given to me by the PS install without any problem.
>
> I know that my 16K tables will be created upfront (I do that on
> purpose) and they'll never affect the rest of the tablespace because
> they're never used. Then I can mix and match the 500K, 1M and 10M
> fixed sizes as much as the available tablespaces let me.

This sounds like a good case for uniform size of 16k for a tablespace. Is this below a minimum limit? I thought you could specify extent management local uniform size 2k if you so desired. Not that I'd recommend that on in normal circumstances <g>.

> I get upset when I have to explain this to the "hotheads" with a
> freshly taken "course" from ORACLE, who come around and point-blank
> whine: "why aren't you using LMTS? It's what ORACLE recommends
> everybody use everywhere!"

But isn't that an excellent question? If irritating. ISTM that Oracle Educations job is to train people in standards and basics and ours is to take these people on. But you need the basics before you can start thinking about applying them. IT would be good if folk that came out of courses knew that they didn't know much (apart from how to pass exams), but you get the same problems with the schools systems in most places. 18 year olds know so much more than 65 year olds after all! It would also help if we all applied Jonathons words from the intro to his book on Oracle books generally "within a year .... it will be 20% misleading,inappropriate or just plain wrong".

> Anyways, that's the core of the problem I had. Education being
> perceived as promoting the thing as a "blanket". It's not always that
> black and white. Most of the time it's bloody dark grey...

You're lucky it doesn't have a reddish tinge from the spilt blood!

Just as an aside does Applications 11i use LMTS everywhere?

--
Niall Litchfield
Oracle DBA
Audit Commission UK