Recently encountered such a problem in the project, customer feedback Caton, Caton statement but has been difficult to optimize, and Caton a lot of places. At this time, the database server performance metrics: cpu40%, wait 10 disk, memory 7G / 64G.
Server performance clearly feel there is not full, say SQLServer is eating memory, a memory but will not eat spit it out, but the memory of this project but there are so many, obviously wrong, I asked some of the company veteran, they let me do not bother memory, disk and CPU did not burst as long as there is no problem. But suffer from not enough memory, the cache has been no implementation plan, then it can not check out the consumption of CPU, disk performance more relevant view some of the statements by the execution plan. Later, after several rounds of Baidu, the original is because the configuration of AWE allocated memory is not turned on, and SQLServer is 32, resulting in SQLServer use up to 4G server memory. Later AWE open configuration, and restart the database server memory finally soared up. Once you have enough memory, CPU and disk pressure also significantly smaller, because you can query the data read from the memory, you can use more memory instead of the tempdb, cpu also because the cache execution plans and reduce the use of .
Summary: CPU and disk pressure may come from low memory, like the barrel of the short board decision barrel capacity memory can not decide, but the impact to a large extent.
Memory cache can not be enough to lead to the implementation plan, for example, some systems view: sys.dm_exec_query_stats no data execution plan
AWE memory usage not increase because allocate memory 32 is not turned on in the SQLServer