In SQL, obtaining partial sums in a grouped aggregation is as simple as adding "WITH ROLLUP" to the GROUP BY clause.
Could we get a "WITH ROLLUP" checkbox in the Summary Tool's confg panel in order to produce partial sums?
(This was initiated as a question here.)
Here is an example of without rollup vs. with rollup, in SSMS:
(Replacing "NULL" with the phrase "(any)" or some such, and we have a very useful set of partial sums.