ADABTPL(ID:2834/ada008)for Abstract DAtaBase Type Programming Language, but pronounced abaptable A high level Pascal-like database language with functional semantics, featuring schemes, domains and tuples as first order types, and domain constraint mechanisms. Structures: References: Introduction Office information systems, because they attempt to Integrate all aspects of a business environment, must be able to deal with a large variety of information types Data that has traditionally been stored m databases such as the typical "supplier and parts" example, must be combined with office objects such as forms, documents and mail. For example, an order form may contain references to suppliers and parts that have their own descriptions A number of data models have been proposed for this application [1,2,3], and the importance in the office of documents with complex structure and multimedia content means that these approaches have strong similarities to other research in multimedia databases [4], which includes applications such as CAD. As well as providing a common language for defining the structure of obJects, a data model can be used to define the valid operations on obJects such as documents This "object-oriented" view of data modeling has been shown to be useful in multimeia applications [4], and can be extended to describe the user operations or tasks that make up office work [5]. Document architecture standards, such as ODA [6], are also designed to be able to represent the possible structures of office documents. The main aim of these architectures is to allow the interchange of documents between open systems. One of the results of this emphasis is that ODA provides for the description of the layout structure of a document as well as the logical structure ODA also specifies constraints on allowable document types, rather than being used only for the specification of types Parts of ODA, therefore, have similarities to the "metaclasses" of object-orIented programing languages [7]. If a data model is used as the basis for an office information system, It must be capable of representing document architecture standards and enforcing them on document type definitions. In this paper, we describe a data model, ADABTPL, that is characterized by formal underpinnings, type constructors, robust subtyping, and extensive constraint mechanisms. We argue that a model with these characteristics 1s essential to represent document architecture standards and their relationship to particular document types. That is, in addition to basic facilities for defining aggregation, generalization and instantiation, a data model should have a formal means for defining constraints on types and specifying how these constraints are inherited and specialized by subtypes. The ADABTPL constraint specification language and manipulation language has a formal semantics that supports mechanical reasoning about Important propertIes of specified systems [8,9] Specifying document architecture standards m ADABTPL gives them a formal semantics and Integrates them with the rest of the office model. in Proceedings of the 1987 ACM SIGMOD international conference on Management of Data ACM SIGMOD Record , 16(3) December 1987 view details in Proceedings of the 1987 ACM SIGMOD international conference on Management of Data ACM SIGMOD Record , 16(3) December 1987 view details in In Proceedings of the Second International Workshop on Object-Oriented Database Systems Sept 1988 view details in Second International Workshop on Database Programming Languages, Salishan, Oregon, Morgan Kaufmann Publishers, Inc., June 1989 view details in Second International Workshop on Database Programming Languages, Salishan, Oregon, Morgan Kaufmann Publishers, Inc., June 1989 view details in IEEE Transactions on Computers July 19, 1991 view details in Computer Languages 17(3) view details in Computer Languages 17(3) view details in Computer Languages 17(3) view details |