Efficient Evaluation of Aggregates on Bulk Types

A new method for efficiently evaluating queries with aggregate functions is presented. More specifically, we introduce a class of aggregate queries where traditional query evaluation strategies in general require O(n) time and space in the size of the (at most two) input relations. For this class of aggregate queries our approach needs at most O(n log n) time and linear space. Further, our approach deals not only with relations but with general bulk types like sets, bags, and lists.