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AAS or the average number or sessions active, shows how many sessions are active on average (over a 5 second range in SQL Query TunerDB Optimizer) and what the breakdown of their activity was. If all the users were running on CPU then the AAS bar is all green. If some users were running on CPU and some were doing I/O, represented by blue, then the AAS bar will be partly green and partly blue.

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The Max CPU is a yardstick for performance on the database. The number of CPUs or Engine on the data source is information SQL Query Tuner obtains DB Optimizer obtains during the profiling process. However, sometimes the number of CPUs or Engines is not reported. In these cases, it might be desirable to change the default number of CPUs/Engines from one to a number more closely matching the actual system running the data source. You might also want to change the Max CPU/Engine line to reflect the performance impact of adding or removing a CPU or Engine from the system.

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* A chart legend displays a color and code scheme for executing and waiting session categories, in the upper right-hand corner of the view.