A temporal query language based on conceptual entities and roles

Elmasri, Ramez; Kouramajian, Vram

doi:10.1007/3-540-56023-8_23

Cited by 8 publications

(6 citation statements)

References 9 publications

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“…This allows us to think about the ways in which the physical computer impacts the domain. Numerous extensions to the ER notation have been defined, notably extensions of cardinality constraints [23,24] extensions that deal with time and history [25,26], extensions with aggregation structures [27,28,29,30,31] and, more recently, sets [32], and extensions with taxonomic structures [27,33,34,35]. Temporal extensions of the ER notation offer ways of expressing constraints on how entities, their relationships and their cardinality constraints can evolve over time.…”

Section: Entity-oriented Approachesmentioning

confidence: 99%

Real-World Semantics of Conceptual Models

Wieringa

2011

Lecture Notes in Computer Science

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Conceptual modelling is the addition of more real-world semantics to the computations performed by a computer. It is argued that in a proper engineering approach to computing, three kinds of conceptual modelling need to be distinguished, (1) modelling a software solution, (2) modelling the domain in which it operates, and (3) modelling the impact of the software solution on the domain. Nearly 40 years of research in conceptual modelling has yielded a wealth of concepts and notations for conceptual modelling of the second variety, which we call domainoriented. A summary and framework of these results are presented. Conceptual modelling of the third variety, which we call impact-oriented, has been developed less. A framework for this is provided too, and promising directions for impact-oriented conceptual modelling are identified.

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Section: Entity-oriented Approachesmentioning

confidence: 99%

Real-World Semantics of Conceptual Models

Wieringa

2011

Lecture Notes in Computer Science

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“…Elmasri et al (I 99 I) and Elmasri & Kouramajian, (1992) introduce the concept of role in the entityrelationship approach to data modeling. In this approach, an entity is a conceptual object that represents real-world entities, and a role of an entity is part of the life-span of an entity.…”

Section: Comparison With Other Approaches To Object Migration and Rolmentioning

confidence: 99%

Using Dynamic Classes and Role Classes to Model Object Migration

Wieringa

Jonge

Spruit

1995

Theory & Prac Object Systems

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In this article, we argue that object-oriented models must be able to represent three kinds of taxonomic structures: static classes, dynamic classes, and role classes, that behave differently with respect to object migration. If CAR is a static subclass of VEHI-' CLE, then a vehicle that is not a car can never migrate to the CAR subclass. On the other hand, if EMPloyee is a dynamic subclass of the PERSON object class, then a PERSON that is not an employee may migrate to EMP. In both cases, an instance of the subclass is identical to an instance of the superclass. By contrast, if EMP is modeled as a role class of PERSON, then every employee differs from every person, but a PERSON instance can acquire one or more EMP instances as roles. The distinctions between the three kinds of classes are orthogonal, so that we can have, for example, dynamic subclass of object or role classes, or role classes of dynamic or static classes.The article is divided into two parts. In the first, informal part, we present an analysis of the differences between the three kinds of classes and motivate their utility by a number of examples. We argue that the inheritance of object life cycles is downward in the static class hierarchy and upward in the dynamic class hierarchy. We summarize this', analysis by giving a number of modeling heuristics that can be used to make sound modeling decisions, and we compare our approach to class migration with other approaches.In the second, formal part of the article, we outline one possible approach to formalizing the specification of static classes, dynamic classes, role classes and class migration, based on order-sorted dynamic logic and process algebra. We illustrate this approach by giving a number of small example specifications and by proving some useful properties of these specifications. This article is an updated and extended version of .

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“…A number of examples of this model can be found in Devor, et al, 1982. The DML used for specifying queries is GORDAS (Graph-ORiented DAta Selection) (Elmasri and Widerhold, 1981). Currently, DDTS is capable of integrating CODASYL-type DBMSs.…”

Section: Heterogeneous Distributed Databases Heterogeneous Distribute...mentioning

confidence: 99%

E-R Approach to Distributed Heterogeneous Database Systems for Integrated Manufacturing

Jain

Bu-Hulaiga

1990

Information Resources Management Journal

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matical models of parts for further analysis. Engineering data are generated and used by analysis packages such as structural and thermodynamic analyses, simulation of motion, and material flow. Each analysis package has unique requirements for data input and output. Most manufacturing data takes the form of a procedural plan or sequence of actions. Textual data are found in all phases of integrated manufacturing from design through marketing; however, the heaviest use is in managerial applications such as production scheduling, cost estimation, quality control, inventory control, sales and marketing.Thus in an integrated manufacturing en-

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A temporal query language based on conceptual entities and roles

Cited by 8 publications

References 9 publications

Real-World Semantics of Conceptual Models

Real-World Semantics of Conceptual Models

Using Dynamic Classes and Role Classes to Model Object Migration

E-R Approach to Distributed Heterogeneous Database Systems for Integrated Manufacturing

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