I occasionally develop multiple data sets from my data source in the process of developing reports in SSRS and then settle on the one best suited for my purposes. Does keeping these unused, not referenced, extra datasets impact the performance of the server in running such reports? If I want to keep the extra datasets for future reference, can I simply comment them out somehow?
Yes, those unreferenced datasets still get executed every time the report is run and could negatively impact your performance.
I verified this by creating a report with three datasets -- only the first one was referenced in the report. Setting up SQL Profiler to watch the database while the report ran shows that all three queries for the three datasets (one used in report, two unused anywhere in report
) were executed.
You could comment out all of the code in the unused datasets in the report, but I would prefer just storing my "working" SQL in a folder on the dev machine.