Re: Locally managed tablespaces or...

Niall Litchfield wrote:

> "dani" <drezustam#QUITAESTO#@airtel.net> wrote in message
> news:b576sa$38k$1_at_nsnmrro2-gest.nuria.telefonica-data.net...
> > Hi,
> > I am planning a 9.2 database, and the locally managed tablespaces are new
> to
> > me, 'cause I came from an 8.0.5.
> > what is better: locally managed tablespaces or dictionary managed
> > tablespaces??
>
> I think that the almost universal conclusion would be to go for locally
> managed tablespaces. They are reliable, faster and enforce policies which
> mean that you will never get extent fragmentation again.
>
> > if so, is it good to set segment space management to auto?? works the
> > bitmaps to manage free space fine?
>
> It sounds like you have two things confused. With LMT's you get
>
> EXTENT ALLOCATION AUTO which allocates extents with one of a preset range of
> sizes (ranging from 64k to 64m) and yes the bitmaps handle free/used extents
> just fine. and
> AUTO SEGMENT SPACE MANAGEMENT which is a new alternative to freelists and
> freelist groups. Generally I'd only recommend using ASSM if you are likely
> to suffer from freelist contention. Not because I distrust ASSM though it is
> a newer feature, but on the if it it aint broke don't fix it principle. ASSM
> wll only benefit certain apps/clients LMTs on the other hand will benefit
> everyone as they remove a bottleneck UET$/FET$ .
>
> --
> Niall Litchfield
> Oracle DBA
> Audit Commission UK

And not only are they better but this is your one and only chance to work with them before 10i renders the dictionary managed tablespaces obsolete.

Daniel Morgan Received on Tue Mar 18 2003 - 10:35:32 CST