1. A computer-implemented method, comprising: accepting, from a data consumer, a consumer command tree expressed in consumer terms; transforming the consumer command tree into a provider command tree expressed in provider terms, wherein the transforming leverages an expression library of a query language that facilitates describing a result shaping function, and wherein alternative versions of compiled functions for result shaping are maintained; producing column map instructions that indicate how to group columns and how to group rows; executing the provider command tree to produce at least one store data reader containing data; applying the column map instructions to the data contained in the at least one store data reader to produce a data reader corresponding to the consumer command tree; and compiling a set of expressions including stateless functions usable in a cache without recompilation.