As part of the Starburst extensible database oroiect. we have designed and implemented a memory resident storage component that can coexist along side traditional disk-oriented storage components. The memory resident storage component shares the code of Starburst'*s common services, such as query optimization, plan generation, query evaluation, record manipu-lation, and transaction management. In this paper, we describe the design of Starburst’s memory resident storage component, contrast it with Starburst’s default disk-oriented storage component, and compare the performance of the two storage components using the Wisconsin Benchmarks. Our results show that a memory resident storage component can perform significantly better than a disk-oriented storage component, even when the disk-oriented storage component has all of its data cached in memory. The benchmark results show that, by using memory resident techniques, overall query execution can be improved by up to a factor of four. © 1992, IEEE. All rights reserved.