Disclosed is a system and method for performing database queries including GROUP-BY operations, in which aggregate values for attributes are desired for distinct, partitioned subsets of tuples satisfying a query. A special case of the aggregation problem is addressed, employing a structure, called the data cube operator, which provides information useful for expediting execution of GROUP-BY operations in queries. Algorithms are provided for constructing the data cube by efficiently computing a collection of GROUP-BYs on the attributes of the relation. Decision support systems often require computation of multiple GROUP-BY operations on a given set of attributes, the GROUP-BYs being related in the sense that their attributes are subsets or supersets of each other. The invention extends hash-based and sort-based grouping methods with optimizations, including combining common operations across multiple GROUP-BYs and using pre-computed GROUP-BYs for computing other GROUP-BYs. An extension of the cube algorithms handles any given collection of aggregates.