Most common database management systems represent information in a simple record-based format. Semantic modeling provides richer data structuring capabilities for database applications. In particular, research in this area has articulated a number of constructs that provide mechanisms for representing structurally complex interrelations among data typically arising in commercial applications. In general terms, semantic modeling complements work on knowledge representation (in artificial intelligence) and on the new generation of database models based on the object-oriented paradigm of programming languages. This paper presents an in-depth discussion of semantic data modeling. It reviews the philosophical motivations of semantic models, including the need for high-level modeling abstractions and the reduction of semantic overloading of data type constructors. It then provides a tutorial introduction to the primary components of semantic models, which are the explicit representation of objects, attributes of and relationships among objects, type constructors for building complex types, ISA relationships, and derived schema components. Next, a survey of the prominent semantic models in the literature is presented. Further, since a broad area of research has developed around semantic modeling, a number of related topics based on these models are discussed, including data languages, graphical interfaces, theoretical investigations, and physical implementation strategies.

An approach to the coordinated sharing and interchange of computerized information is described emphasizing partial, controlled sharing among autonomous databases. Office information systems provide a particularly appropriate context for this type of information sharing and exchange. A federated database architecture is described in which a collection of independent database systems are united into a loosely coupled federation in order to share and exchange information. A federation consists of components (of which there may be any number) and a single federal dictionary. The components represent individual users, applications, workstations, or other components in an office information system. The federal dictionary is a specialized component that maintains the topology of the federation and oversees the entry of new components. Each component in the federation controls its interactions with other components by means of an export schema and an import schema. The export schema specifies the information that a component will share with other components, while the import schema specifies the nonlocal information that a component wishes to manipulate. The federated architecture provides mechanisms for sharing data, for sharing transactions (via message types) for combining information from several components, and for coordinating activities among autonomous components (via negotiation). A prototype implementation of the federated database mechanism is currently operational on an experimental basis.

In this paper, we overview the Object-Protocol Model (OPM) and a suite of data management tools based on OPM. OPM is a data model that allows specifying database structures and queries in terms of objects and protocols specific to scientific (e.g., molecular biology laboratory) applications. Thus, scientific experiments and their resources can be described using OPM in a unified way. OPM data management tools provide facilities for specifying and querying relational databases in terms of OPM constructs, and automatically generate database specifications and queries for implementing OPM on top of commercial relational database management systems (DBMSs). OPM tools increase the efficiency of developing scientific databases using relational DBMSs, while insulating scientists from the underlying DBMSs. Key words: data management tools, object data model, scientific database 1. INTRODUCTION Keeping track and querying data generated by scientific experiments, simulations, and measurements re...

In a class hierarchy, a “role set ” is t,he set of classes where an object may reside simultaneously. A “migration pattern ” is a sequence of role sets. A “migration inventory, ” which is a set, of migrat,ion patterns, is viewed as a dynamic const,raintm on ohjrct migration. A set of transact ious is “sound ” wrt a11 inventory if it. generates only pat.t.t~rns in the invrntory; “complete ” if all pat,terns in the invent,ory can be generated. An initial stucly on characterizing migration inventories of transact,ions is presented. Three update languages are considered: SL which contains five operat,ors, CSL+ which ext rn(ls SL wit.h posit.ivc conditionals, and CSL which allows hot,h positive and negative condit.ionals. Four kinds of invent.orics are studied based on ln~znrss and znj~~,rtl~ntr s/art. It is shown that inventories produced by SL t,ransactions are regular and every regular inventory can be generated by SL transactions. Soundness and complet,eness for SL t,ransactions are decidahlt3. lnvc\llt,orics gpnrrated by CSL (CSL+) t,ra.nsactions arc r.e‘. and every r.e. inventory can be generat,rd by (:SL+ (CSL) transa.ctions under nonimmediate st,art,. It is also show t,hat, every r.e. immediate-start invent,ory can be obtained by a left quotient, of t,he invent,ory of CSL+ (CSL) transactions hy a regular seb. The exact, charact#erizat.ions are open. However, cvrry contrxl-frcr srt can be generat,ed. Soundness and rmllplPt~enms for ($1, (CSL+) t,ransa.ctions are undecidahlr. 1

The 3-Dimensional Information Space (3DIS) is an extensible object-oriented framework for infor-mation management. It is specifically oriented toward supporting the database requirements for data-intensive information system applications in which (1) information objects of various levels of abstraction and modalities must be accommodated, (2) descriptive and structural information (metadata) is rich and dynamic, and (3) users who are not database experts must be able to design, manipulate, and evolve databases. In response to these needs, the 3DIS provides an approach in which data and the descriptive information about data are handled uniformly in an extensible framework. The 3DIS provides a simple, geometric, and formal representation of data which forms a basis for understanding, defining, and manipulating databases. Several prototype implementations based upon the 3DIS have been designed and implemented and are in experimental use.

Business Artifacts are the core entities used by businesses to record information pertinent to their operations. Business operational models are representations of the processing of business artifacts. Traditional process modeling approaches focus on the actions taken to achieve a certain goal (verb-centric). Business artifact-centric modeling starts by identifying what is acted upon (noun-centric), and constructs business operational models by identifying the tasks/actions that business actors execute to add business value. In this paper, we identify important classes of properties on artifact-centric operational models. In particular, we focus on persistence, uniqueness and arrival properties. To enable a static analysis of these properties, we propose a formal model for artifact-centric operational models. We show that the formal model guarantees persistence and uniqueness. We prove that, while checking an arrival property is undecidable in general, under a restricted version of the formalism, an arrival property can be checked in EXPTIME. 1

Object --- a non-value object in the real world. An abstract object can be, for example, a tangible item (such as a person, a table, a country), or an event (such as an offering of a course by an instructor), or an idea (such as a course). Abstract objects cannot be represented directly in the computer. This term is also used for a user-transparent representation of such an object in the Semantic Binary Model. Category (also called Entity# Type# or Entity# Set# in some semantic models) --- any concept of the application's real world which is used for classification of objects. At every moment in time such a concept is descriptive of a set of objects. Unlike the mathematical notion of a set, the category itself does not depend on its objects: the objects are added and removed while the meaning of the category is preserved in time. Conversely, a set does depend on its members: the meaning of a set changes with the ebb and flow of its members. Categories are usually named by singular ...

The specification of communication behavior is fundamental in developing interoperable transactions. In particular, the temporal ordering of messages exchanged between different communicating agents must be declaratively specified and verified in order to guarantee consistency of data in the various component systems. This paper shows that by expressing communication constraints in propositional temporal logic, the tableau method can be applied to construct a dependency graph. If the specification is correct, this method guarantees that all possible execution paths satisfying the specification will be generated. The declarative specification and verification of communication constraints in interoperable transactions is demonstrated using the classic business trip. It is argued that the specification formalism provides an improvement over the Flexible Transaction Model.