Does anybody know:
With the PIData.Summary method, where the SummaryType is astCount and CalculationBasis is cbEventWeighted, does the server simply read in all the events in the time range and count them, or does it use some faster shortcut mechanism? Presumably this would also apply to all the other methods of invoking a summary calculation such as DataLink or PE (EventCount).
I suppose my question in a nutshell is: Is there a quick way to for a client to get the number of compressed events for a tag in a time range with minimal impact on the server? I don't care about knowing what percent of events are good. The time ranges I am thinking about are 5 years or more so you can understand my concern. I need to be able to report back to the user how long a data retrieval is likely to take so he has the option to "chunk" it.