Systems which manipulate important volumes of data need to be managed with Real-Time (RT) databases. These systems are subject to several temporal constraints related to data and to transactions. Thus, their design remains a complex task. To remedy this complexity, it is necessary to integrate design methods to support data and transactions temporal constraints. Among the design methods, those based on patterns have been widely used in several fields. However, despite their advantages, these patterns present some shortcomings. Indeed, they do not manage efficiently the patterns variability and they do not specify the pattern elements when they are instantiated. To overcome these limitations, we propose, in this paper, a new UML profile to (i) express the variability in patterns and (ii) to identify the pattern elements in its instance. Besides, in order to well-capture the knowledge of the domain, the proposed profile extends UML with concepts related to real-time databases and integrates OCL (Object Constraint Language) to enforce the variation points consistency. Finally, we give an example of a RT pattern that illustrates these UML extensions, where we implement the proposed profile and we validate the pattern diagrams using the constraints we have proposed.