Re: Algorithm for calculating extent size in LMT

Hi,

Thanks for the Insight ... I Think i Missed That ...

And with due Respect to Thomas Kyte... The Link below...

http://asktom.oracle.com/pls/ask/f?p=4950:8:563325::NO::F4950_P8_DISPLAYID,F4950_P8_CRITERIA:240014552942,%7BStorage%7D

He States that ....

<Quote>
For Locally managed tablespaces (the only kind I use in Oracle8i) The storage parameters NEXT, PCTINCREASE, MINEXTENTS, MAXEXTENTS, and DEFAULT STORAGE are not valid. They are totally ignored. The storage parameter INITIAL is only used if the tablespace is not UNIFORMALLY sized (I myself use UNIFORM, not AUTOALLOCATE in which case the initial can be specified).
</QUOTE>

Your Comments Tom...
Anyways Some more Questions Embedded.

"Jonathan Lewis" <jonathan_at_jlcomp.demon.co.uk> wrote in message news:<1015319425.22836.0.nnrp-14.9e984b29_at_news.demon.co.uk>...
> There is a degree to which initial, next, minextents
> are used even with LMTs. Oracle will calculate
> the nominal space requested according to these
> values, and then supply you with a number of
> extents according to its own policy that at least
> match that size.
> E.g. in an LMT with uniform 2M, if you set
> initial = 3M, next = 10 M, minextents = 5,
> then Oracle will calculate
> 3 + 4 * 10 = 43
> and supply you with a starting size of 22 extents
> (i.e. the smallest number of extents that gives
> you at least 43MB).
>
> It's harder to predict in an autoallocate, since it
> depends on what empty space actually exists
> already, but there is a fair chance that your
> starting segment would have
> 3 x 1MB and 5 x 8MB.

Sorry lost you here !!! What is the Logic Behind this.

>
>
>
> --
> Jonathan Lewis
> http://www.jlcomp.demon.co.uk
>
> Now running 3-day intensive seminars
> http://www.jlcomp.demon.co.uk/seminar.html
>
> Host to The Co-Operative Oracle Users' FAQ
> http://www.jlcomp.demon.co.uk/faq/ind_faq.html
>
> Author of:
> Practical Oracle 8i: Building Efficient Databases
>
>
> Ganesh Raja wrote in message ...
> >Comments Embedded
> >
> >Regards,
> >Ganesh R
> >
> >"EP" <ep_at_plusnet.pl> wrote in message news:<a60ff8$isp$1_at_news.tpi.pl>...
> >> > There is no such thing. Extent sizes are determined by developers and
> DBAs
> >> > that do their homework and determine the idea size for a class of
> tables.
> >> > Often ... creating multiple tablespaces with different extent sizes to
> avoid
> >> > both fragmentation and keep the number of segments ?small.
> >>
> >> You are mistaken here, as with the autoallocate option you also have to
> >> calculate such parameters as INITIAL, NEXT and MINEXTENTS, so DBA
> homework
> >> is done as well !!!
> >
> >Are You Sure... I Feel you are talking about Dict Managed TBS and
> >that is almost History now considering 9i is pushing for LMT's in a
> >Big way.
> >
> >LMTS Dont use the Initial Next and MinExtents they are ignored when a
> >TBS is declared as a LMT.
> >
> >> As far as the number of extens goes, Oracle's calculation is based on
> the
> >> above parameters, so you don't need to worry about too many extents
> (unless
> >> you have made a mistake while estimating these parameters).
> >
> >Absolutley Wrong ... See above !!!
> >
> >>
> >> Regards,
> >> EP
Received on Wed Mar 06 2002 - 02:31:53 CST