Today's database management systems (DBMSs) are required to handle diverse, mixed workloads and to provide differentiated levels of service to ensure that critical work takes priority. In order to meet these needs, it is necessary for a DBMS to have control over the workload executing in the system. Lower priority workloads should be limited to allow higher priority workloads to complete in a timely fashion. In this paper we examine query throttling techniques as a method of workload control. In our approach, a workload class may be slowed down during execution in order to release system resources that can be used by higher priority workloads. We examine two methods of throttling; constant throttling throughout query execution, and a single interruption in which a query is paused for a period of time. A set of experiments using Postresql 8.1 provides insights regarding the performance of these different throttling techniques under different workload conditions and how they compar...