AbstractThis paper illustrates the implementation feasibility of an optimistic approach to concurrency control. After reviewing the approach and clarifying the underlying algorithms and assumptions, it is applied to the design of a multi‐user version of an existing relational database management system. Two different system architectures for a UNIXUNIX is a trademark of Bell Laboratories. ‐based environment are presented and prototype implementations have been constructed. We also provide some performance statistics on the optimistic approach to concurrency control and compare it with a traditional locking protocol.