Re: Oracle statistics

From: Richard Foote <richard.foote_at_bigpond.com>
Date: Sat, 14 Sep 2002 00:13:01 +1000
Message-ID: <lemg9.31151$g9.89997@newsfeeds.bigpond.com>

Hi Norman,

I have *proven* that having data in one extent is preferable and improves performance.

I had a table with 10,000,000 rows in 2,500 extents. It took ages to perform a full table scan, obviously because of the number of extents, right.

So guess what I did.

I deleted 9,999,990 rows, exported the table, re-imported the table in only *1* extent.

Now the full table scan runs heaps and heaps quicker, again obviously because now the table is only in the *1* extent.

*PROOF* !! Can't help thinking I've overlooked something though ...

Richard ;)
"Norman Dunbar" <Norman.Dunbar_at_lfs.co.uk> wrote in message news:E2F6A70FE45242488C865C3BC1245DA702A5450C_at_lnewton.leeds.lfs.co.uk...
> Afternoon Gents,
>
> why would anyone drop and import all their data ......
> Don't you just *know* it's going to be 'to get it all into one extent
> for better performance' :o)
>
> Cheers,
> Norman.
>
> -------------------------------------
> Norman Dunbar
> Database/Unix administrator
> Lynx Financial Systems Ltd.
> mailto:Norman.Dunbar_at_LFS.co.uk
> Tel: 0113 289 6265
> Fax: 0113 289 3146
> URL: http://www.Lynx-FS.com
> -------------------------------------
>
Received on Fri Sep 13 2002 - 09:13:01 CDT