Event Driven Computations for Relational Query Language

Proceedings of the 1-st International Workshop on Computer Science and Information Technologies CSIT'99, Moscow, Russia, 1999. Vol.1, pp. 43--52 This paper deals with an extended model of computations which uses the parameterized families of entities for data objects and reflects a preliminary outline of this problem. Some topics are selected out, briefly analyzed and arranged to cover a general problem. The authors intended more to discuss the particular topics, their interconnection and computational meaning as a panel proposal, so that this paper is not yet to be evaluated as a closed journal paper. To save space all the technical and implementation features are left for the future paper. Data object is a schematic entity and modelled by the partial function. A notion of type is extended by the variable domains which depend on events and types. A variable domain is built from the potential and schematic individuals and generates the valid families of types depending on a sequence of events. Each valid type consists of the actual individuals which are actual relatively the event or script. In case when a type depends on the script then corresponding view for data objects is attached, otherwise a snapshot is generated. The type thus determined gives an upper range for typed variables so that the local ranges are event driven resulting is the families of actual individuals. An expressive power of the query language is extended using the extensional and intentional relations.