Proposes a new lock primitive called ordered sharing that allows increased concurrency in database systems. Reliability and performance issues of the proposed protocol are addressed, a simulation study that demonstrates that ordered sharing results in improved performance in database systems is described; and use in several representative database…

Presents an access method for temporal data called the Snapshot Index that reconstructs a past state of a time-evolving collection of objects. Previous approaches to temporal access methods are reviewed, and migrating data to write-once optical disks are discussed. (Author/LRW)

Discussion of local area networks and multiple file servers for concurrent information retrievals provides a rationale for workload and data allocation and presents an analytical model which will attain effective allocation policies. Nonlinear integer programming is discussed, and computational results show the effectiveness of the heuristic.…

Discussion of methodologies for the semantic integration of databases focuses on formalizing the notion of schema equivalence and the schema integration process. Topics include common data model; the Entity-Relationship (ER)model; transformation of ER models; transformational, mapping, and behavioral schema equivalence; and knowledge-based…

Discussion of data repositories available in global information systems focuses on facilitating access by providing semantic views. Highlights include the mapping relation; syntax and semantics of the mapping; query formulation and processing; terminological systems for semantic views; and relational algebraic expressions. (LRW)

Presents an improved inverted region quadtree variation called Dynamic Inverted Quadtree that is able to support and index a pictorial database. Pattern-searching algorithms are described, and the space needs of Fully Inverted and Dynamic Inverted Quadtrees are analytically compared based on a model of image randomness expressed as a branching…

Discussion of multimedia computing and multimedia information systems that contain audio and video data focuses on how to implement buffer sharing in continuous-media systems based on slots and portions. Disk utilization and transition periods are considered, and future work is described. (LRW)

Discussion of hypermedia systems focuses on a comparison of two types of adaptive algorithm (genetic algorithm and neural network) in clustering hypermedia documents. These clusters allow the user to index into the nodes to find needed information more quickly, since clustering is "personalized" based on the user's paths rather than…

Discusses indexes for text databases and presents an efficient implementation of an index for text searching called PAT array, or suffix array, where the database is stored on secondary storage devices such as magnetic or optical disks. Additional hierarchical index structures and searching algorithms are proposed that improve searching time, and…