Towards a Role-Based Contextual Database

Traditional modeling approaches and information systems assume static entities that represent all information and attributes at once. However, due to the evolution of information systems to increasingly context-aware and self-adaptive systems, this assumption no longer holds. To cope with the required flexibility, the role concept was introduced. Although researchers have proposed several role modeling approaches, they usually neglect the contextual characteristics of roles and their representation in database management systems. Unfortunately, these systems do not rely on a conceptual model of an information system, rather they model this information by their own means leading to transformation and maintenance overhead. So far, the challenges posed by dynamic complex entities, their first class implementation, and their contextual characteristics lack detailed investigations in the area of database management systems. Hence, this paper, presents an approach that ties a conceptual role-based data model and its database implementation together, to directly represent the information modeled conceptually inside a database management system. In particular, we propose a formal database model to describe roles and their contextual information in compartments. Moreover, to provide a context-dependent role-based database interface, we extend RSQL by compartments. Finally, we introduce RSQL Result Net to preserve the contextual role semantics as well as enable users and applications to both iterate and navigate over results produced by RSQL. In sum, these means allow for a coherent design of more dynamic, complex software systems

A UML profile for multidimensional modeling in data warehouses

The multidimensional (MD) modeling, which is the foundation of data warehouses (DWs), MD databases, and On-Line Analytical Processing (OLAP) applications, is based on several properties different from those in traditional database modeling. In the past few years, there have been some proposals, providing their own formal and graphical notations, for representing the main MD properties at the conceptual level. However, unfortunately none of them has been accepted as a standard for conceptual MD modeling. In this paper, we present an extension of the Unified Modeling Language (UML) using a UML profile. This profile is defined by a set of stereotypes, constraints and tagged values to elegantly represent main MD properties at the conceptual level. We make use of the Object Constraint Language (OCL) to specify the constraints attached to the defined stereotypes, thereby avoiding an arbitrary use of these stereotypes. We have based our proposal in UML for two main reasons: (i) UML is a well known standard modeling language known by most database designers, thereby designers can avoid learning a new notation, and (ii) UML can be easily extended so that it can be tailored for a specific domain with concrete peculiarities such as the multidimensional modeling for data warehouses. Moreover, our proposal is Model Driven Architecture (MDA) compliant and we use the Query View Transformation (QVT) approach for an automatic generation of the implementation in a target platform. Throughout the paper, we will describe how to easily accomplish the MD modeling of DWs at the conceptual level. Finally, we show how to use our extension in Rational Rose for MD modeling.This work has been partially supported by the METASIGN project (TIN2004-00779) from the Spanish Ministry of Education and Science, by the DADASMECA project (GV05/220) from the Regional Government of Valencia, and by the MESSENGER (PCC-03-003-1) and DADS (PBC-05-012-2) projects from the Regional Science and Technology Ministry of Castilla-La Mancha (Spain)

Conceptual Modeling for Federated Geographical Information Systems over the Web

A conceptual model provides the best support for federating heterogeneous datastores into a unified framework and elaborating a global consistent description of all available data. It therefore plays a central role for exchange of information within the coming information society. This paper introduces a conceptual model for applications using spatio-temporal data. We discuss in particular the features which support spatial and temporal modeling. An example of conceptual design is given using a pedology application. Advantages of our approach for database design are assessed through comparison with traditional geographical information systems modeling techniques

Conceptual modeling of multimedia databases

The gap between the semantic content of multimedia data and its underlying physical representation is one of the main problems in the modern multimedia research in general, and, in particular, in the field of multimedia database modeling. We believe that one of the principal reasons of this problem is the attempt to conceptually represent multimedia data in a way, which is similar to its low-level representation by applications dealing with encoding standards, feature-based multimedia analysis, etc. In our opinion, such conceptual representation of multimedia contributes to the semantic gap by separating the representation of multimedia information from the representation of the universe of discourse of an application, to which the multimedia information pertains. In this research work we address the problem of conceptual modeling of multimedia data in a way to deal with the above-mentioned limitations. First, we introduce two different paradigms of conceptual understanding of the essence of multimedia data, namely: multimedia as data and multimedia as metadata. The multimedia as data paradigm, which views multimedia data as the subject of modeling in its own right, is inherent to so-called multimedia-centric applications, where multimedia information itself represents the main part of the universe of discourse. The examples of such kind of applications are digital photo collections or digital movie archives. On the other hand, the multimedia as metadata paradigm, which is inherent to so-called multimedia-enhanced applications, views multimedia data as just another (optional) source of information about whatever universe of discourse that the application pertains to. An example of a multimedia-enhanced application is a human-resource database augmented with employee photos. Here the universe of discourse is the totality of company employees, while their photos simply represent an additional (possibly optional) kind of information describing the universe of discourse. The multimedia conceptual modeling approach that we present in this work allows addressing multimedia-centric applications, as well as, in particular, multimedia-enhanced applications. The model that we propose builds upon MADS (Modeling Application Data with Spatio-temporal features), which is a rich conceptual model defined in our laboratory, and which is, in particular, characterized by structural completeness, spatio-temporal modeling capabilities, and multirepresentation support. The proposed multimedia model is provided in the form of a new modeling dimension of MADS, whose orthogonality principle allows to integrate the new multimedia modeling dimension with already existing modeling features of MADS. The following multimedia modeling constructs are provided: multimedia datatypes, simple and complex representational constraints (relationships), a multimedia partitioning mechanism, and multimedia multirepresentation features. Following the description of our conceptual multimedia modeling approach based on MADS, we present the peculiarities of logical multimedia modeling and of conceptual-to-logical inter-layer transformations. We provide a set of mapping guidelines intended to help the schema designer in coming up with rich logical multimedia document representations of the application domain, which conform with the conceptual multimedia schema. The practical interest of our research is illustrated by a mock-up application, which has been developed to support the theoretical ideas described in this work. In particular, we show how the abstract conceptual set-based representations of multimedia data elements, as well as simple and complex multimedia representational relationships can be implemented using Oracle DBMS

Spatio-Temporal Conceptual Models: Data Structures + Space + Time

Nowadays, many applications need data modeling facilities for the description of complex objects with spatial and/or temporal facilities. Responses to such requirements may be found in Geographic Information Systems (GIS), in some DBMS, or in the research literature. However, most of existing models cover only partly the requirements (they address either spatial or temporal modeling), and most are at the logical level, hence not well suited for database design. This paper proposes a spatio-temporal modeling approach at the conceptual level, called MADS. The proposal stems from the identification of the criteria to be met for a conceptual model. It is advocated that orthogonality is the key issue for achieving a powerful and intuitive conceptual model. Thus, the proposal focuses on highlighting similarities in the modeling of space and time, which enhance readability and understandability of the model

Modeling views in the layered view model for XML using UML

In data engineering, view formalisms are used to provide flexibility to users and user applications by allowing them to extract and elaborate data from the stored data sources. Conversely, since the introduction of Extensible Markup Language (XML), it is fast emerging as the dominant standard for storing, describing, and interchanging data among various web and heterogeneous data sources. In combination with XML Schema, XML provides rich facilities for defining and constraining user-defined data semantics and properties, a feature that is unique to XML. In this context, it is interesting to investigate traditional database features, such as view models and view design techniques for XML. However, traditional view formalisms are strongly coupled to the data language and its syntax, thus it proves to be a difficult task to support views in the case of semi-structured data models. Therefore, in this paper we propose a Layered View Model (LVM) for XML with conceptual and schemata extensions. Here our work is three-fold; first we propose an approach to separate the implementation and conceptual aspects of the views that provides a clear separation of concerns, thus, allowing analysis and design of views to be separated from their implementation. Secondly, we define representations to express and construct these views at the conceptual level. Thirdly, we define a view transformation methodology for XML views in the LVM, which carries out automated transformation to a view schema and a view query expression in an appropriate query language. Also, to validate and apply the LVM concepts, methods and transformations developed, we propose a view-driven application development framework with the flexibility to develop web and database applications for XML, at varying levels of abstraction

Modeling of Traceability Information System for Material Flow Control Data.

This paper focuses on data modeling for traceability of material/work flow in information layer of manufacturing control system. The model is able to trace all associated data throughout the product manufacturing from order to final product. Dynamic data processing of Quality and Purchase activities are considered in data modeling as well as Order and Operation base on lots particulars. The modeling consisted of four steps and integrated as one final model. Entity-Relationships Modeling as data modeling methodology is proposed. The model is reengineered with Toad Data Modeler software in physical modeling step. The developed model promises to handle fundamental issues of a traceability system effectively. It supports for customization and real-time control of material in flow in all levels of manufacturing processes. Through enhanced visibility and dynamic store/retrieval of data, all traceability usages and applications is responded. Designed solution is initially applicable as reference data model in identical lot-base traceability system