Thank you for reaching us through community.
Advanced Data Sets (ADS) are reports that can be run on demand with user defined filters such as dates and org units. The value of ADS’s is that they answer specific questions on their own without having to join with another data set. They are great for ad hoc investigations. ADS’s can be downloaded through the UI or accessed through APIs.
Amount of time the report to get generated depends on the data and can vary
You can have a look at the following article for some quick regerences.