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Re: Performance difference between 2 machines

From: Fabrizio <fabrizio.magni_at_mycontinent.com>
Date: Wed, 22 Jun 2005 22:01:19 GMT
Message-ID: <Pclue.31024$b5.1395791@news3.tin.it>


Sybrand Bakker wrote:

>>For the "db file scattered read" I'd try to enable (if not already) the 
>>async i/o (this can make a big difference for batch jobs) and to adjust 
>>the DB_FILE_MULTIBLOCK_READ_COUNT.

>
>

Since I'm not sleeping yet...

> One of the most common problems I see is some 'dba's enable
> disk_async_io on Unix, even when the file is not on a RAW volume, or
> on a volume using the proper edition of Veritas.

disk_async_io? I was referring to OS aio but since we are here: disk_async_io is enabled by default on 9i (the OP version).

And on a filesystem you need to set FILESYSTEMIO_OPTIONS at, at least, asyncio!

While on linux you have even to relink the binaries!

> On Solaris it is quite easy to demonstrate in that case all
> asynchronous calls will fail, after which Oracle reissues the call as
> an ordinary pread or pwrite.

We were discussing of UP-UX and linux here. However solaris as a good kaio (maybe the best available).

Are you referring to a veritas bug? Or solaris one? Which version? Have you contacted support?

> Depending on the configuration of the OP your advice may have a
> dentrimental effect.
>

What's a test case made for?
Nothing better than to test for himself!

-- 
Fabrizio Magni

fabrizio.magni_at_mycontinent.com

replace mycontinent with europe
Received on Wed Jun 22 2005 - 17:01:19 CDT

Original text of this message

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