Re: Number of extents related with performance?

        I am using Oracle 8.0.6.1 and solaris 2.6.

        The result make me feel that the size of extents is so important in creating the objects.

David
Nuno Souto wrote:
>
> On Fri, 29 Dec 2000 00:44:54 -0800, Jimmy <anonymous_at_anonymous.com>
> wrote:
>
> > I've read news and documents about the effect on the performance
> >when the number of extents of object is increased. Most of it (even on
> >Oracle Metalink) just mentioned that the performance is not related with
> >the number of extents (except dropping and truncating tables). However,
> >when I query the table that has about 800000 rows (about 200M storage
> >spaces) with over 100 extents (extent size is 32K), it takes about 10
> >second to return the number of rows. When I increase the extent size to
> >64M (number of extents is now 3), it just takes 2 seconds.
> >
> > Could anyone tell me is there any relationship between the performance
> >and the number of extents of an object? (in my case, both tables are
> >newly created, so no fragmentation) It seems that, as my case, decrease
> >the number of extents can increase the query performance.
> >
>
> Sounds awful. I have not yet been able to prove conclusively that
> number of extents is significant for performance since V7. Wasn't
> really on V6 either, but few people knew what to do to init.ora to
> stop the problem.
>
> Which version and what OS you running this on?
>
> I'm curious, because it is against my experience so far in later
> versions of ORACLE. In fact, since V7 I have taken take the "easy
> space management" approach explained in a paper by Himatzinga and
> Loaitza a while ago and have never looked back.
>
> Cheers
> Nuno Souto
> nsouto_at_bigpond.net.au.nospam
> http://www.users.bigpond.net.au/the_Den/index.html
Received on Sun Dec 31 2000 - 01:54:03 CST