INTERNAL - Why are certain drilldowns not being populated with data?
We will use the I/O drilldown as an example. Development would like to clarify Spotlight’s functionality as it doesn’t collect data for all drilldowns at all times. If this were to be implemented, it would put unacceptable load on SQL Server. Instead, it populates some drilldowns only when a relevant alarm occurs, so that the relevant drilldown data can be subsequently viewed in History mode.
The Diagnostics I/O drilldown is one of the drilldowns. It is a relatively expensive query to retrieve the data, so the query is only run if the user manually navigates to the drilldown, or if an I/O Wait Time alarm occurs.
So unless that alarm is triggered, that drilldown will indeed be intentionally blank in history mode.