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RE: 32-bit vs. 64-bit on HP-UX 11.0

From: Deshpande, Kirti <>
Date: Fri, 29 Mar 2002 12:59:30 -0800
Message-ID: <>


 Following is from the LazyDBA list.
 Any 64-byters on this list seen this ??? If so, can you please share you experience and findings?
- Kirti

-----Original Message-----

Sent: Wednesday, March 20, 2002 1:37 PM
To: Discussion

Don't upgrade, export, recreate the database and import or you will not get full benefit from 64 bit. At one client we saw a 300% performance boost on some processes by rebuilding the instance from scratch verses just migrating.


----Original Message-----

Sent: Wednesday, March 20, 2002 2:52 PM

 Can you please elaborate, as to how exactly going 64-bit this way helped boost the performance by 300%?

 Don't you think that export/import helped some by eliminating chained rows (if any), reducing or eliminating block level fragmentation, reducing blevels in indexes etc.
 Or there weren't any of these issues to be concerned with.

 Just curious.. as we are pondering on such a move in the very near future...


-----Original Message-----

Sent: Wednesday, March 20, 2002 2:00 PM
To: 'Deshpande, Kirti'

Nope, they migrated the instance, then exported, dropped and imported back into the migrated instance as part of the testing process, then used the export to build a new 64 bit database. When the performance of the old migrated but rebuilt database was tested against the new imported database the processes that did many IOs, such as updates, took up to 300% longer on the migrated instance.

Both instances where on the same host going against the same disk array. the initialization parameters where identical. The migrated instance showed nearly 300-400 percent more consistant gets for the same process leading me to believe it is some type of internal byte splicing technique being used to emulate the 64 bit environment in the migrated instance while true 64 bit is used in a "new" 64 bit instance.

Exporting the migrated database, dropping the instance and recreating then importing brought the performance back in line with the other instance. really odd.


-----Original Message-----

Sent: Friday, March 29, 2002 12:34 PM
To: Multiple recipients of list ORACLE-L

I think that Oracle is actually concentrating on the 64 bit now. Especially on HP. Personally I would go 64 bit. There seems to be no specific bugs that are 64 bit related (although I would do your own research on that one). Therefore, all that would happen is that you would be potentially limiting yourself by going 32-bit whereas sky's the limit if you choose the other route.


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Author: Deshpande, Kirti

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