Query Using Aggregate or Detail Data

I have recently been doing some research regarding when it is acceptable to build aggregate tables in addition to the detail fact tables. A couple articles I have read mentioned tools that can issues queries that determine whether there is an aggregate table that can be used to answer the issued query or if it should retrieve data from the detailed fact table. The articles didn't mention specific tools. Is this a capability of some BI tools out there?

Business Objects provides aggregate awareness and will use an aggregate table if it is appropriate for the query being asked. It's a bit tricky to set up however. Other BI tools provide similar functionality (I believe Cognos and Microstrategy do, but I do not know first-hand).