The rapid advances in the development of low-cost computer hardware have led to many proposals for the use of this hardware to improve the performance of database management systems. Usually the design proposals are quite vague about the performance of the system with respect to a given data management application. In this paper we predict the performance of several of the proposed database management machines with respect to several representative INGRES queries. The systems analyzed in this paper include associative disks, RAP, CASSM, DBC, DIRECT, and CAFS. We demonstrate that no one database machine is best for executing all types of queries. We will also show that for one class of queries the degree of performance improvement achieved does not warrant use of a database machine.