An approach to determining an appropriate file structure for a given application is presented, by outlining a methodology for comparing some important aspects of data management system performance. The aspect chosen for analysis is the processing time required to evaluate Boolean functions defined on data values contained within a file structure and select elements from the structure satisfying the expression.Two file structures are studied. The structures are each combinations of hierarchical and inverted file organizations, which differ in the use of the pointers contained in the inverted file. In one case they link a value to nodes corresponding to its occurrence in the data hierarchy and in the second they link a value to the entry which contains the node corresponding to an occurrence.Algorithms for processing within each of the structures are discussed. Each algorithm is then modeled, and approximating models developed for simulation of the algorithms.