Re: extents

Tom Best wrote:
>
> Nuno:
>
> If PCTINCREASE is 0, then do you make it a habit to manually defragment on
> occasion (since Oracle only defrags if PCTINCREASE > 0)?
>
> Thanks,
> Tom Best
>
> Nuno Souto <nsouto_at_nsw.bigpond.net.au.nospam> wrote in message
> news:3986a84e.1963144_at_news-server...
> > On Mon, 31 Jul 2000 06:57:02 -0700, Mark D Powell
> > <mark.powellNOmaSPAM_at_eds.com.invalid> wrote:
> >
> > >depend mostly on your tablespace space management policies. I
> > >believe that Oracle currently recommends to assign the same
> > >extent size to all objects in the tablespace, initial=next and
> > >pctincrease=0. This makes every free extent available for use
> > >by any object that needs to extend. I think it is more
> > >important to organize large objects this way than it is for
> > >small objects.
> >
> > Hehehe! They _finally_ recomending that? Been using it since V6, 12
> > yaears ago...
> >
> > On another note: going this way, it's handy to separate your database
> > into volatile tables and static tables. Then for each group, there
> > should be a "small" tablespace, a "middle" tablespace and a "large"
> > tablespace. Not necessarily in overall size but more to do with the
> > default storage parameters of the each tablespace. And of course, try
> > to have all extents within the same tablespace the same size. That
> > makes free space and used space management and defragmenting easy as
> > pie.
> >
> > This is a minimum. Of course, there are more refinements to make, but
> > that's highly case-by-case.
> >
> > HTH
> >
> > Cheers
> > Nuno Souto
> > nsouto_at_nsw.bigpond.net.au.nospam
> > http://www.users.bigpond.net.au/the_Den/index.html

Why would you need to ???

If you tablespace has 'n' chunks of of size (say) 100M, then any new object in that tablespace is going to request chunks of size 100M. You don't have a fragmentation problem if every chunk is the same size...That is the whole reason for having tablespace with a uniform extent size policy

HTH

-- 
===========================================
Connor McDonald
http://www.oracledba.co.uk

We are born naked, wet and hungry...then things get worse