Query language in systems with hard real-time constraints

In order to provide the news demands that a real-time database needs to work properly, some improvements have been proposed in aspects well done like concurrency control, scheduling and query language. In the perspective of obtain better results, despite the accomplished efforts, these problems continuous been studied. In this paper we introduce a new query language for real-time database (QL-RTDB), that's an extension of the structured query language (SQL-99). Besides the new functionalities of the extended language presented, we also show its implementation with the applied results obtained.