State of the Art Review on Hypermedia Issues And Applications
Vaidheyar Raman Balasubramanian · 1999
Machine (HAM) [Consens & Mendelzon, 1989]. It addresses the following issues raised by Halasz: Search and query mechanisms, augmentation of the basic node and link model, virtual structures, computation over the hypertext network, and versioning. Using GraphLog, queries are formulated by drawing graph patterns. These patterns are then searched for in the hypertext network to yield subgraphs. GraphLog is highly expressive and it uses the notions of deductive database theory and descriptive complexity. The language is powerful enough to allow the specification and manipulation of arbitrary subsets of the network and supports the computation of aggregate functions on the subgraphs of the hypertext document. It can support dynamically defined structures as well as inference capabilities. GraphLog is an extension of the graph-based query language called G+. G+ was extended by adding the notions of negation, aggregation, and improved semantics to make it simple, yet powerful. It can express ...