Re: Database Performance

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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