Query processing and optimization in temporal object-oriented databases

Investigates temporal query processing and optimization in the context of object-oriented databases. Based on our temporal object data model and algebra, a strategy of decomposition is presented to process temporal queries that involve associations of both aggregation hierarchy and time-reference. That is, the evaluation of an enhanced path, which is defined to extend a path with time-reference, is decomposed by initially dividing the path into two sub-paths: one contains the time-stamped class that can be optimized by making use of the ordering information of temporal data and another in an ordinary sub-path which can be further decomposed and evaluated using different algorithms. The intermediate results of traversed two sub-paths are then joined together to create the query output. Algorithms of time-related operations and four basic join algorithms have been implemented with stream processing techniques and presented with a cost analysis. Optimization issues have been discussed.