Re: Fragmentation query

I'm only familiar with "standard" Oracle setups on Netware3 (soon to be NT/Win2K server). Supposedly Netware automatically does disk "optimization" internally, so defragging is never an issue. I'm not sure exactly what that means, but I was told that the Netware cache architecture basically makes defragging unneccessary.

However, some issues may be worth mentioning: as long as the database is shutdown, it is relatively trivial to move database files around (eg, to different volumes/directories), and then reconfigure the database to see the files in the new location. This leads me to think that there is some independence between the database and underlying file system, at least in the sense that Oracle doesn't depend on explicit static physical location of disk data below the granularity level of "logical" calls to OS file operations. Otherwise it would seem that Oracle recovery would require that database files be put back in the exact same physical tracks/sectors they were originally, and that seems *highly* unlikely.

However, I would guess that running disk defrag on NT/Win2K server while the database is open would be a pretty bad idea, but I could easily be wrong.

(To make things murky, in Netware, Oracle says you can't use OS volume compression or block sub-allocation with Oracle database files, at least not "reliably" for long.)

hopefully people will correct any of the above as necessary, ep

On 14 Sep 2000, at 9:05, O'Neill, Sean wrote:

Date sent:      	Thu, 14 Sep 2000 09:05:18 -0800
To:             	Multiple recipients of list ORACLE-L <ORACLE-L_at_fatcity.com>
Send reply to:  	ORACLE-L_at_fatcity.com
From:           	"O'Neill, Sean" <Sean.ONeill_at_organon.ie>
Subject:        	Fragmentation query

> Hi Folks,
>
> I'd like to try and understand the issues, if any, between fragmentation of
> a disk from operating system perspective vs fragmentation from Oracle's
Received on Thu Sep 14 2000 - 19:23:44 CDT