Re: Locally Managed Tablespaces - any cons???

On Sat, 11 Aug 2001 07:37:05 +1000, "Howard J. Rogers" <howardjr_at_www.com> wrote:

>
>"Kenneth Koenraadt" <plovmand_at_hotmail.com> wrote in message
>news:3b7197c5.7098447_at_news.mobilixnet.dk...
>>
>> On Tue, 7 Aug 2001 21:20:37 -0600, "Ron Gardiner"
>> <rongardiner_at_powersurfr.com> wrote:
>>
>> >New for 8i (I believe) is locally managed tablespaces...
>> >
>> >From what I've read, sounds like there is no reason NOT to use them. Can
>> >they be used for all types of TS?... rollback segs, temporary, how about
>> >system itself?
>> >
>> >Any feedback would be appreciated!
>> >
>> >
>> >
>> Hi Ron,
>>
>> You cannot create a locally managed SYSTEM tablespace on database
>> creation. But you can convert it to LM later with a supplied package.
>>
>> The SYSTEM tablespace and the tablespaces for rollback segments must
>> have the same extent management type, so if you convert the SYSTEM
>> Tablespace to LMT, rememer to convert your RBS tablespace(s) to LMT as
>> well.
>>
>
>This is just not true.
>
>Firstly, whilst you may be able to convert SYSTEM into a LMT, it's strongly
>advised not to. You may have noticed that SYSTEM also has 50% PCTINCREASE,
>which is generally bad, and is autoextensible, which is also usually
>considered not terribly efficient... but the point is, SYSTEM breaks all the
>rules, and is best left to do so. LMT/DMT is just another example.
>
>Secondly, you appear to suggest that if SYSTEM is DMT, you must have DMT
>rollback segment tablespace. Absolutely not true. Provided there is one
>non-system rollback segment created (and brought online), you can create a
>LMT rollback tablespace, and create (and online) one LMT'd rollback
>segment... after which, the original DMT'd rollback segment can be dropped,
>and all others created without a problem. And all of that can be done
>perfectly well with a SYSTEM tablespace that is merrily chugging a way as
>dictionary-managed.
>
>Incidentally, the SYSTEM tablespace in 9i is still dictionary managed, and
>there is still no provision for creating it Locally Managed... yet another
>indication that locally managed SYSTEM tablespace is not advised, nor
>necessary.
>
>Regards
>HJR
>
>
>
>
>> Regards,
>> Kenneth Koenraadt
>> Systems Consultant
>> Oracle DBA
>> plovmand@<no-spam>hotmail.com
>
>

I have revisited the Oracle Documentation, and must admit I cannot prove my statement. The only restriction is that rollback segments cannot be created in a System managed tablespace.(AUTOALLOCATE).

Now, you tell ME :

Exactly WHERE does the documentation recommend not to convert SYSTEM tablespace to LMT, thus advising you not to use the built-in package which does just that piece of work ??

Regards,
Kenneth Koenraadt
Systems Consultant
Oracle DBA
plovmand@<no-spam>hotmail.com Received on Sat Aug 11 2001 - 11:01:14 CDT