Report Performance - Date folder vs Indexed Custom field

Hi,

we are working on our report performance. There is a dashboard report which is particular slow. This is caused as it is prompted for a date range on a Indexed Custom Date Field.

We did some experiments and noticed that it is _much_ faster when we switch to the "Date Closed" field instead. I think I read in this forum that it is advised to switch to this "Date Folder" dates instead to the dates of the driving subject. Our tests back this up. Now I read in the report performance document of 2011 that especially for filter the folder dates should not be used but the date fields from the record type itself.