RAMFS and Oracle TMP Segment

From: <alexandr.antonov_at_barclays.com>
Date: Thu, 31 Jul 2014 10:29:51 +0100
Message-ID: <BB54F5B84B72C841B4D4CB2C1D98C20E0237BE8E72_at_LDNPCMMGMB03.INTRANET.BARCAPINT.COM>



Hi List

We are assessing an option of moving our TMP segment files to a ramfs file system. The Temporary tablespace is 40 GB in size. A colleague of mine raised a concern that if we make only one tempfile 40gb in size we might face a performance degradation when multiple session would write into tmp segment because of the file locking.

Now I believe that the described problem does not hold water cause assuming two processes running on two different CPUs trying to write into two different addresses in RAM would still be serialised on a shared bus. Am I right here? Regardless of that, from the file system implementation POV, would writes block the file?

Finally, I know that the data changes are written to disk by the database writer process(es). Can anyone describe (or point me at the corresponding reading) how Oracle is writing into the temporary segment?

Our database id on RHEL5.9 x64

Thanks anyone who responds.

Regards

Alex


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Received on Thu Jul 31 2014 - 11:29:51 CEST

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