Bill,

It sounds like you are describing an ideal situation.  Is this scan being
done by only one user at a time?  Then you are describing a dedicated
database to one user?

Lets face it, the above is not even remotely probable in todays world.  And
furthur, if you decided that the above setup is what you want, then how do
you apply new records to the table - a full reload every time?  It seems way
to much work in hopes that the resulting query might be faster.

In my humble opinion, there seems to be *way* too much time devoted to
worrying about table extents and disk access.  Disk are soo much faster
today, that I've decided that it really is not worth considering very much.
Of course, I'm not currently working on a high-volume application right now,
so my radar is focused on other things.

Interesting idea, though.

Tom Mercadante
Oracle Certified Professional


-----Original Message-----
Sent: Wednesday, February 27, 2002 7:43 AM
To: Multiple recipients of list ORACLE-L




I know this one has been done to death:  use uniform extents to avoid 
fragmentation; multiple extents don't hurt (within limits).

But what if:

Data Warehouse, one big table on a single disk, full table (batch) scan, no 
concurrent transactions on the database (so no contention for the disk), no 
fragmentation at the file system level, initially empty buffer cache 
(startup), read-only operation so DBWR isn't doing anything on this 
disk.  Basically I want to read one data file from end to end.  Surely it 
would make sense to have the disk read moving smoothly from one end of the 
disk to the other rather than bouncing about all over the place as it may 
do with multiple extents "randomly" allocated.

Any thoughts?

Thanks
- Bill.

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Bill Buchan
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).
-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.com
-- 
Author: Mercadante, Thomas F
  INET: [EMAIL PROTECTED]

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Reply via email to