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Home -> Community -> Mailing Lists -> Oracle-L -> RE: Old Chestnut: Tablespace Fragmentation
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
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: Bill Buchan
INET: wbuchan_at_uk.intasys.com
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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: ListGuru_at_fatcity.com (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). Received on Wed Feb 27 2002 - 09:03:27 CST
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