A real-time database system (RTDBS) can be defined as a database system where transactions are associated with real-time constraints. In this paper, we investigate various performance issues in a RTDBS constructed on a client-server system architecture. In a client-server database management system the whole database is stored on the server disks, and copies of database items can be cached in the client memories. We provide a detailed simulation model of a client-server RTDBS, and present the initial results of a performance work that evaluates the effects of various workload parameters and design alternatives. Index Terms - Real-time database systems, client-server architecture, transaction scheduling, timing constraints