For the extension of high-level languages by data types of mode relation, three language constructs are proposed and discussed:- a repetition statement controlled by relations- predicates as a generalisation of boolean expressions- a constructor for relations using predicates.The language constructs are developed step by step starting with a set of… (More)
Scoping, naming and binding are central concepts in the deenition and understanding of programming languages. With the introduction of sophisticated data models, these issues become important for query languages as well. Additionally, the goal of integrating query and programming languages requires a common basis for their operational semantics. We ooer… (More)
A Three-Facet Information D ealing with change is one of the most fundamental challenges facing IS professionals today. Business process restructuring, shifting alliances and new competitors , deregulation and globalization , legacy system migration, and new technology adoption, are but a few of the economical, organizational , and technological forces… (More)
Relational databases use predicates for a large variety of different functions. some leading to database search, others being handled by theorem proving. First we demonstrate that the theorem provinr! applications have very similar basic requirements for predicate mana-eement but differ in their need foti efficiency. Second we Gresent dedicated deduction… (More)
We present a framework for the development of information systems based on the premise that the knowledge that influences the development process needs to somehow be captured, represented, and managed if the development process is to be rationalized. Experiences with a prototype environment developed in ESPRIT project DAIDA demonstrate the approach. The… (More)
On February 4-5, 1988, the International Computer Science Institute sponsored a two day workshop at which 16 senior members of the data base research community discussed future research topics in the DBMS area. This paper summarizes the discussion which took place.
Innovative information systems such as content management systems and information brokers are designed to organize a complex mixture of media content – texts, images, maps, videos,. .. – and to present it through domain specific conceptual models, for example, on sports, stock exchange, or art history. In this paper we extend the currently dominating… (More)