RE: Stop defragmenting and start ...

  • From: "Cary Millsap" <cary.millsap@xxxxxxxxxx>
  • To: <oracle-l@xxxxxxxxxxxxx>
  • Date: Thu, 10 Jun 2004 21:08:21 -0500

I don't think 160KB is silly given that _bump_highwater_mark_count (sp?)
defaults to 5. I know it looked weird to a lot of people, but once you
consider that Oracle moves the highwater mark moves in increments of 5 (and
this is a sensible value), the silly thing is how people set their
multiblock read count to a power of 2.


Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com
* Nullius in verba *

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-----Original Message-----
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Mogens Nørgaard
Sent: Thursday, June 10, 2004 4:39 PM
To: oracle-l@xxxxxxxxxxxxx
Subject: Re: Stop defragmenting and start ...

Cary thought about it, and argued for many equally sized extents. 
Another guy - Stern? Stein? - inside Oracle wrote an excellent article 
where he used the metaphor of tiles on the bathroom floor, I think. Did 
not Tim Gorman also mumble about this stuff on the Oracle HelpKern list?

The trouble with Juan's paper initially was the rather silly 160K sizes, 
etc. to compensate for the rounding stuff. With LMT's that need 
disappeared and we could go back to 128, etc. At least that's how I 
remember it.

Mogens

Lex de Haan wrote:

> Robyn,
> 
> I quickly checked my courseware archives,
> and for sure Cary Millsap talked about uniform extent sizes in 1996.
> to be more precise: he probably talked about this even before 1996,
> but my private collection does not contain any hard evidence :-)
> 
> Kind regards,
> Lex.
>  
> ---------------------------------------------
> visit my website at http://www.naturaljoin.nl
> ---------------------------------------------
> 
> 
> -----Original Message-----
> From: oracle-l-bounce@xxxxxxxxxxxxx
> [mailto:oracle-l-bounce@xxxxxxxxxxxxx]On Behalf Of Robyn
> Sent: Thursday, June 10, 2004 16:02
> To: oracle-l@xxxxxxxxxxxxx
> Subject: Stop defragmenting and start ...
> 
> 
> Hello,
> 
> Can someone tell me when uniform extent sizing became a recommended
> practice?  The 'Stop defragmenting and Start Living' paper has a copyright
> date of 1998, and I remember implementing it on some databases back in
> 1999, but I was wondering if it there were earlier references to this
> approach.
> 
> Robyn
> 
> ----------------------------------------------------------------
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