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Oracle Performance Firefighting, written by
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The experimental results also show that although IMU operations are performed in memory, and memory management consumes CPU resources, CPU resources were significantly reduced when using IMU. If you think about that, it's actually quite an amazing accomplishment.
Based on my understanding of IMU, the experimental results, and understanding Oracle performance analysis, unless there are kernel issues with IMU (which there have been), I would always keep IMU enabled. With IMU enabled, you can expect Oracle to consume a significantly less amount of CPU.
IMU setup and monitoring is quite simple because Oracle automatically enables IMU by default. Only eight instance parameters directly affect IMU, and IMU activity is recorded just like any other Oracle internal activity.
©2009, 2010 by Craig Shallahamer. This is copyrighted material.
PleaseOut of respect for those involved in the creation of the book and also for
their familes, we ask you to respect the copyright both in intent and deed. Thank you.
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