You can use the SQL PI Compare where differences in period activity illustrate underlying performance and monitoring issues. It helps you determine whether a comparison occurrence is an isolated incident or a sign of a potentially significant performance problem.
The comparison can be of whole instances or selected dimension breakdowns (such as user or SQL).
After identifying the different resource usage, you can use compare to identify what caused this difference: Usage pattern? Different SQL behavior? Environmental problem?
The upper panes graphically displays the Workload or any other selected resource.
The middle Activity section displays the dimensions which were significant elements of the difference. Expanding the individual lines displays the dimension members which caused the difference and the composing metrics whose differences exceed the specified threshold.
Use the set of performance related metrics (defined by the chosen resource) to help you explain the difference in resource consumption; for example, a rise in I/O Wait might be explained by a rise in the quantity of physical reads.
Use the Comparison Parameters section in order to enter all the desired information for the cooperation. For example, time range, instance, dimension, time frames, resource.