Hi.
You start with 35000 rows.
Avg. row size 42 bytes.
So you need at least 42 * 35000 = 1470000 bytes in initial extent.
Add some overhead for Oracle control info and for pctfree -
so make it 2M.
I would make it even bigger ( if space is not a problem right now ).
HTH. Michael.
In article <38EDF013.B039BDC9_at_dteenergy.com>,
Gregory P Lechkun <lechkung_at_dteenergy.com> wrote:
>
> --------------796931C59B998121866E5321
> Content-Type: text/plain; charset=us-ascii
> Content-Transfer-Encoding: 7bit
>
> Hello,
>
> I'm tuning a table for size, extents, pctfree, and pctused. Here are
> some of the statistics on the table:
>
> block_size 8192
> initial_extent 16384
> next_extent 1048576 -- This was originally 8192 before it was
> adjusted
> max_extents 505
> num_rows 35698
> blocks 315
> empty_blocks 60
> avg_space 3011
> avg_row_len 42
> pctfree 10
> pctused 40
>
> Now, in this table, every row will eventually be deleted. The table
is
> being used as a circular buffer in a FIFO manner, and rows are never
> updated, just deleted. Presently, the oldest row in the table is
dated
> March 12, but a majority of the rows will be cleared out within 7-10
> days. This table will start off at the 35,000 rows and within a year
> will have 1,000,000 rows.
>
> I'm figuring I'm going to set the initial_extent & next_extent to
> 1048576, and setting the pctfree = 5 and pctused = 90 (Kevin Loney's
DBA
> Handbook suggest pctused should be 95-pctfree).
>
> - Does this sound reasonable for a table that has such volatile data?
> - Will having such values in the pctfree & pctused cause a performance
> issue?
>
> --
> Regards,
> Greg Lechkun
> gpl :-)
>
> DTE
>
Energy==================================================================
==
>
> DTE ////// //////////// Gregory Lechkun - EM&D/PDO-PT
> DTE // // // // Power Application Software Engineer
> DTE // // // //// lechkung_at_detroitedison.com
> DTE // // // // g.p.lechkun_at_ieee.org (personal)
> DTE ////// // ////// (313)235-9445 Office (313)940-3306
> Pgr.
> (313)235-8597 FAX
>
> --------------796931C59B998121866E5321
> Content-Type: text/html; charset=us-ascii
> Content-Transfer-Encoding: 7bit
>
> <!doctype html public "-//w3c//dtd html 4.0 transitional//en">
> <html>
> <tt>Hello,</tt>
> <p><tt>I'm tuning a table for size, extents, pctfree, and
pctused.
> Here are some of the statistics on the table:</tt>
> <p><tt>block_size
8192</tt>
> <br><tt>initial_extent 16384</tt>
> <br><tt>next_extent 1048576 --
This
> was originally 8192 before it was adjusted</tt>
> <br><tt>max_extents
505</tt>
> <br><tt>num_rows
> 35698</tt>
>
<br><tt>blocks &nbs
p;
> 315</tt>
> <br><tt>empty_blocks
60</tt>
>
<br><tt>avg_space
> 3011</tt>
>
<br><tt>avg_row_len  
;
> 42</tt>
>
<br><tt>pctfree &nb
sp;
> 10</tt>
>
<br><tt>pctused &nb
sp;
> 40</tt><tt></tt>
> <p><tt>Now, in this table, every row will eventually be deleted.
> The table is being used as a circular buffer in a FIFO manner, and
rows
> are never updated, just deleted. Presently, the oldest row in
the
> table is dated March 12, but a majority of the rows will be cleared
out
> within 7-10 days. This table will start off at the 35,000 rows
and
> within a year will have 1,000,000 rows.</tt><tt></tt>
> <p><tt>I'm figuring I'm going to set the initial_extent &
next_extent
> to 1048576, and setting the pctfree = 5 and pctused = 90 (Kevin
Loney's
> DBA Handbook suggest pctused should be 95-pctfree).</tt><tt></tt>
> <p><tt>- Does this sound reasonable for a table that has such volatile
> data?</tt>
> <br><tt>- Will having such values in the pctfree & pctused cause a
> performance issue?</tt>
> <br><tt></tt> <tt></tt>
> <p><tt>--</tt>
> <br><tt>Regards,</tt>
> <br><tt>Greg Lechkun</tt>
> <br><tt>gpl :-)</tt>
> <p><tt>DTE
Energy==================================================================
==</tt>
>
<br><tt>DTE ////// ////////////  
;
> Gregory Lechkun - EM&D/PDO-PT</tt>
>
<br><tt>DTE // // // //&
nbsp;
> Power Application Software Engineer</tt>
>
<br><tt>DTE // // // //// 
;
> lechkung_at_detroitedison.com</tt>
>
<br><tt>DTE // // // // &
nbsp;
> g.p.lechkun_at_ieee.org (personal)</tt>
>
<br><tt>DTE ////// // ////// &n
bsp;
> (313)235-9445 Office (313)940-3306 Pgr.</tt>
>
<br><tt> &nbs
p; &nbs
p;
> (313)235-8597 FAX</tt>
> <br> </html>
>
> --------------796931C59B998121866E5321--
>
>
Sent via Deja.com http://www.deja.com/
Before you buy.
Received on Sat Apr 08 2000 - 00:00:00 CDT
