SSRS Query Timeout vs DatabaseQuery Timeout In SSRS there are appear to be two separate query timeout options. The Query Timeout option can be found in the Dataset Properties dialog window on the Query tab. The DatabaseQuery Timeout option is found in the rsreportserver.config file. I realize the Query Timeout option is specific to the dataset, and the DatabaseQuery Timeout option is specific to Report Server.

What are the reasons for using different settings? Why not just make the Query Setting to always default to the overall report server DatabaseQuery setting? If I have a lower DatabaseQuery setting will that timeout before the Query setting is met?

Edit: I also want to know if this is in fact a serverside setting that can be overriden with the report specific setting. I can't seem to find any documentation on how these two settings are related/different.
I once supported an application that would timeout certain queries after 300ms (not a reporting system). If that application were to default to a server level setting, they wouldn't have been able to achieve the different timeouts that the business required. This is an extreme case of course, but it's an example of why you might want different settings at the server and data set level.