Re: Database Performance

I also dont like to see more than 10 extents... Although I bet your performance is query related and not storage related...

Randy

sybrandb_at_my-deja.com wrote:

> In article <39570A25.33DB2FBC_at_hotmail.com>,
> kskasi_at_hotmail.com wrote:
> > Hello everyone
> >
> > The problem is that, the biggest table we have in our system has got
> > only about 50,000 records. But the system seems to be slow even with
> > those many records. Our DBA feels that enough space wern't alloted to
> > the tables and they might be sitting in multiple extends. I had a look
> > at the extends and I did notice that there are about 7 - 10 extends
 for
> > the big table and some of the indexes. According to him, if there are
> > more number of extends then oracle has to search through all the
 extends
> > which takes more time. I had a look at Oracle documentation and it
> > dosen't mention about this at all. I just want a second opinion on
 this
> > before I drop the tables and recreate them with enough space. I guess
 I
> > can rebuild the indexes with enough space but the tables has to be
> > dropeed and reloaded. Any help would be appreciated
> >
> > Cheers...kasi
> >
> >
>
> Searching through extents applies to full table scans and likely fast
> full index scans. Oracle will never read more than one extent at a
> time. IMO, have a fragmented index is much more harming your
> performance than a table in a few extents, assuming you have infrequent
> full table scans.
> However, the critical limit is for me 10 extents. Whenever your object
> has more, defragment it.
>
> Hth,
> --
> Sybrand Bakker, Oracle DBA
>
> All standard disclaimers apply
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Received on Fri Jul 07 2000 - 00:00:00 CDT