Re: Why does a datafile extend a very large amount at very infrequent intervals?

From: Rich <richa03_at_gmail.com>
Date: Tue, 10 Jul 2012 16:21:01 -0700
Message-ID: <CALgGkeC5ukpVu4B9sHjSSWT2QV7L=xbzp_Q9zXrD1JaU8sM4Ww_at_mail.gmail.com>

[removing the rest of the email chain to prevent getting over-quoting] Finally found the answer to this one (with no help from Oracle Support) - it's due to the new [in 11g] Oracle process ora_smco. This process "performs tablespace-level space (extent) pre-allocation".

This is noted in Oracle Note 743773.1 (last modified 13APR2012).

Another thing to potentially note about this is that this process spawns slave processes (ora_w###).

On our instance, we also see these processes consuming more CPU time than expected - this is bug 12760469: STBH: KTSJ USES CONSIDERABLE AMOUNT OF DATABASE TIME/CPU RESOURCE. This bug is supposed to be fixed in 11.2.0.4.

Rich

Including keywords such that a search will hopefully find this: NEXT_EXTENT DBA_DATA_FILES INCREMENT_BY

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Received on Tue Jul 10 2012 - 18:21:01 CDT