Re: Database Performance

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

Multiple extents aren't really a problem in itself. But it *CAN* be if you've got a some full table scans going on: Since multiple extents *typically* are scattered all over the place, the disk heads do need to move a lot, which slows things down.

But then again, this is only if you've got full table scans going on. And you shouldn't really need full table
scans on such big tables anyway; perhaps time to check your indexes??

Hope this helps

--

Karl E. Jorgensen

Note: Reply address is bogus - use k a r l _at_ j o r g e n s e n . c o m instead