Summary form only given. Recently, the demand for real-time data services has been increasing. Many e-commerce applications and information services are requiring sophisticated real-time data support. A database is a core component for such real-time applications. Important to the functionality of real-time databases is data replication, which is used to meet critical time requirements. These requirements vary with different workloads; therefore, different methods of replication control are better suited for different workloads. We examine several methods of replication control and present two new methods for distributed real-time database systems. Our methods are more ideally suited for systems with non-static periodic transaction arrival patterns and systems with random transaction arrival patterns.