Howard J. Rogers wrote:
>>Hey Richard,
>>
>>DMT gives you more options when it comes to extent sizes in a single
>>tablespace.
>
>
> Come off it! WHY would you want 'more options' along these lines? give me
> one good reason why you think it desirable to be able to create 500 segments
> with 500 different extent sizes in the same tablespace.
>
> There are *no* such good reasons. It all comes down to design, and if your
> particular business "needs" so many different extent sizes, then it's
> because someone doesn't know what they're talking about.
>
>
>>What Oracle wants to do in the future is really besides the point.
>
>
> No it's not, actually. The fact that they will abolish DMTs means that they
> recognise the inefficiencies associated with them, and wish to eliminate the
> inefficiencies. You'd be a fool not to want to eliminate them also.
>
>
>>I am not
>>even sure
>>if we will use Oracle if it comes to 10i.
>
>
> Fair enough. But that doesn't negate the fact that Oracle (in this
> particular case, just for once) isn't pushing LMTs because marketing thinks
> it sounds good, but because there are storage and performance benefits in
> making the switch. Not to mention less hassles for DBAs. Though I realise it
> makes it a bit tough for any DBA who is desperately searching for a
> justification for their job, and thinks 'space management' is a compelling
> argument.
>
>
>>In the mean time we will continue
>>to use DMT
>>until we have to make a choice between uniform LMT - the one-size-fit-all
>>approach
>
>
> What on earth is 'one size fits all' about LMTs? Are you in any way
> prevented from creating a tablespace where the uniform size is 97K? Or
> 4302K? or 2636K? No you are not.
>
>
>>or system LMT - the brain dead approach. :)
>
>
> What's brain dead is claiming that auto-allocate is brain-dead. It is a very
> efficient, and rather elegant algorithm that has all the benefits of LMTs
> regarding no contention on the Data Dictionary, and yet manages to utterly
> minimise the possibility of fragmentation.
>
> No one (apart from Oracle Corporation) will be forcing you to use LMTs in
> the near future, so I am not suggesting that you're not entitled to your
> opinion, or that others shouldn't feel free to share it. But please don't
> post bunkum about LMTs capabilites, or the 'advantages' of DMTs. Nothing you
> have posted stands up to technical scrutiny, and some of things you've
> posted just invite the response: you apparently don't know how to manage a
> database. Which I'm sure is not true: but there's a difference between a
> genuine business need and base prejudice.
>
> HJR
>
>
Good afternoon Howard,
I think this remark is along the route of 'using autoextending
tablespaces is lazy DBA approach'.
I -personally- disagree, provided an automated
system monitoring tools is in place and being used.
Just returned from a client with performance issues, and thay
have all users granted dba role, or "else the software won't run".
Resulted in a huge amount of indexes being created in SYSTEM tablespace,
which is now totally cluttered. Some objects had ##,### extents...
Advised to go LMT... And upgrade to the latest patch level.
Among others.
Cheers,
Frank
Received on Wed Feb 05 2003 - 10:49:28 CST
