In environments where the state of the system changes rapidly, such as stock trading, air traffic control, network management, and process control, databases have been proposed as the platform to develop automated control systems. Information in such systems consists of "updates," reporting on the state of the environment and…

Discussion of database management tools for scientific information focuses on the Object Protocol Model (OPM) and data management tools based on OPM. Topics include the need for new constructs for modeling scientific experiments, modeling object structures and experiments in OPM, queries and updates, and developing scientific database applications…

Presents the design and implementation of a deductive object-oriented database which is built upon a formally defined data model that uses two languages: an imperative programming language called ROCK (Rule Object Computation Kernel), and a logic language called ROLL (Rule Object Logic Language). (LRW)

This paper addresses the problem of data management techniques for efficiently retrieving requested subsets of large data sets from mass storage devices. Describes the development of algorithms and software that facilitate the partitioning of a large data set into multiple "clusters" that reflect their expected access. (Author/JKP)

Shows how counterfactuals and machine learning methods can be used to guide exploration of large databases that addresses some of the fundamental problems that organizations face in learning from data. Discusses data mining, particularly in the financial arena; generating useful knowledge from data; and the evaluation of counterfactuals. (LRW)

Performance is a critical factor hindering the use of object-oriented databases (OODB). This article proposes a new and uniform indexing scheme for enhancing OODBs with advantages for small range, clustered sets queries. Reviews several other indexing schemes; presents the U-index scheme; discusses its performance; and presents experimental…

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)

Considers a "hybrid" approach to the modeling of uncertainty in deductive databases. The model, deductive IST (DIST) is based on an extension of the "Information Source Tracking" (IST) model for relational databases. Proves that the complexity of testing containment of conjunctive DIST queries remains the same as in the…

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…

Presents a seven-step methodology for utilizing integrity constraint knowledge from heterogeneous databases. Describes generating a set of integrity constraints applicable at the integrated level from constraints specified on local databases. Introduces the concept of constraint-based relationships between objects in heterogeneous databases;…