José María Cavero

A methodological approach for object-relational database design using UML

Abstract.The most common way of designing databases is by means of a conceptual model, such as E/R, without taking into account other views of the system. New object-oriented design languages, such as UML (Unified Modelling Language), allow the whole system, including the database schema, to be modelled in a uniform way. Moreover, as UML is an extendable language, it allows for any necessary introduction of new stereotypes for specific applications. Proposals exist to extend UML with stereotypes for database design but, unfortunately, they are focused on relational databases. However, new applications require complex objects to be represented in complex relationships, object-relational databases being more appropriate for these requirements. The framework of this paper is an Object-Relational Database Design Methodology, which defines new UML stereotypes for Object-Relational Database Design and proposes some guidelines to translate a UML conceptual schema into an object-relational schema. The guidelines are based on the SQL: 1999 object-relational model and on Oracle8i as a product example.

Extending UML for Object-Relational Database Design

The most common way of designing databases is using de E/R model without taking into account other views of the system. However, new object-oriented design languages, such as UML (Unified Modelling Language), permit modelling the full system, including the database schema, in a uniform way. Besides, as UML is an extensible language, it allows introducing new stereotypes for specific applications if it is needed. There are some proposals to extend UML with stereotypes for database design but, unfortunately, they are focused on relational databases. However, new applications require representing complex objects related with complex relationships and object-relational databases are more appropriated to support the new application requirements. The framework of this paper is an Object-Relational Database Design Methodology. The methodology defines new UML stereotypes for Object-Relational Database Design and proposes some guidelines to translate an UML schema into an object-relational one. The guidelines are based on the SQL:1999 object-relational model and on Oracle8i as an example of product. In this paper we focus on the UML extensions required for object-relational database design.

Model transformation for object-relational database development

In this paper we define and formalize the model transformations that complete the methodological approach for the development of Object-Relational (OR) Databases (DB) proposed in MIDAS, a model driven methodology for the development of Web Information Systems. In this proposal the Platform Independent Model is the conceptual data model while the Platform Specific Model is the Object-Relational model that represents the OR DB schema. Since both of them will be represented in UML, we also summarize an UML profile for OR DB modeling. In this work we focus on the formalization of the mappings needed to get the OR DB schema from the conceptual data model. We have first specified them with natural language to later formalize them with graph transformation rules.

MIDAS/BD: A Methodological Framework for Web Database Design

One of the most important trends in Information System research is concerning Web application development. Generally, Web Information Systems are developed ad-hoc, that is, without modeling them before their implementation. At best, developers use techniques and methodologies directly imported from the traditional Software Engineering field. However, classic methodologies do not fit to some key aspects of Web applications as, for example, navigation design. This is the reason why different modeling techniques and methodologies for Web Information Systems development have appeared. MIDAS is a methodological framework for Web Information System development that can be customized according to the type of application we want to develop (hypermedia applications, database applications, etc.). In this paper we present MIDAS/BD, the specific part of MIDAS for Web Database development. MIDAS/BD is based on XML and (object -) relational technology.

The Road Toward Ontologies

One of the most important characteristics of today’s society is that a huge amount of information is shared by many participants (people, applications). This information must be characterized by a uniformity of terms. This means that, in similar contexts, everyone should understand the same meaning when reading or hearing the same word and everyone should use the same word to refer to the same concept. In different Computer Science disciplines one of the methods that satisfies this need for “common understanding” of concepts is the creation of ontologies. Curiously, there are different interpretations of what ontology is. In this chapter, we show the way that the concept of ontology has expanded from Philosophy into Computer Science.

Participation of women in software engineering publications

To the best of our knowledge, no works analyzing the participation of women as authors and editors in software engineering research publications currently exist. We have therefore followed a well-defined procedure in order to conduct an empirical study of female participation in 12 leading software engineering journals. We have analyzed the gender of the authors, editorial board members, associate editors and editors-in-chief over a two-year period in order to analyze, on the one hand, the rate of participation of women as authors and as editors in software engineering publications, and on the other, whether women are underrepresented. We have also analyzed the female distribution of authors and editors according to the geographical location of their institutions. This was done by first selecting the journals to be used as the population for data collection which then allowed us to identify female authors of papers and female editors, including the country in which their institutions are located. This eventually led to an analysis of female participation in order to understand representation rates. We analyzed 3,546 authors of 1,266 papers in 61 different countries, and 363 members of editorial boards in 30 different countries. The results of this analysis provide quantitative data concerning the participation of women as authors and editors in major software engineering journals including their distribution per country, in which important differences have been found. The results obtained were first used to compare the participation of women as authors and editors and were then used to carry out a series of simulations in order to be able to statistically confirm whether women are underrepresented. The study shows, amongst other things, that women are not underrepresented as editorial boards members and as editors-in-chief of the journals studied, although their representation as editors-in-chief is low.

Toward UML-Compliant Semantic Web Services Development

The emerging Semantic Web and, in particular, Semantic Web services SWS, demands the inclusion of new components in applications involving this technology. Therefore, Web development methodologies must be tailored to support the systematic development of such new components. In previous works we presented a UML profile, which extends the SOD-M method for service oriented Web Information System development of the MIDAS model-driven framework, to address the development of Semantic Web Services using WSMO Web Service Modeling Ontology. The UML profile allows for the modeling of the new elements required by WSMO Web Services. This article focuses on studying the possibility of improving the proposed UML profile, including the OCL Object Constraint Language, for the representation of WSMO logical axioms through three case studies. This would allow developers, whose knowledge does not extend beyond UML, to develop applications that use Semantic Web services.

Computer science research: more production, less productivity

It is commonly accepted that scientific research or, more precisely, the number of scientific publications, in computer science has greatly increased over the last few years. The reason would appear to be the pressure to publish, coined by the expression ”Publish or perish”, which is, among other things, necessary for promotions and applications for grants or projects. In this paper we have conducted a study that covers computer science publications from 1936 to 2010 in order to quantify this increase in publications regarding computing research. We have considered the computing conferences and journals available in the DBLP computer science bibliography (DBLP 2013) database, including more than 1.5 million papers, and more than 4 million authors (more than 900,000 different people), corresponding to about 1,000 different journals and 3,000 different conferences and workshops. Our study confirms and quantifies these increases with regard to the number of papers, number of authors, number of papers per author, etc. However, it also reaches a surprising conclusion: the real productivity of researchers has decreased throughout history. The reason for this decrease is the average number of authors per paper, which has grown significantly and is currently three.

The concepts of model in information systems engineering: A proposal for an ontology of models

Modelling is one of the most frequent tasks in the area of information systems (ISs), with models such as schemata, ontologies, patterns and architectures forming the bases for their creation. Very often, however, the difference between these types of models is not clear and causes confusion and erratic use of the terms. The aim of this paper is to clarify the concept of model through a study of some of the more common ones used in ISs. This proposal is presented through an ontology, where we show how we conceptualize models according to their role in the development of an IS: the model understood as the representation of a domain or as a reality serving as an example.

Hierarchies in Object Oriented Conceptual Modeling

One of the most powerful tools of abstraction used in objectoriented conceptual modelling is the specialisation/generalisation hierarchy, which allows representing taxonomic relationships among classes. A specialisation/generalisation hierarchy (from now on, taxonomy or taxonomic hierarchy) has always two main associated characteristics: the classification and the inheritance concepts. There are, however, different kinds of taxonomic hierarchies (classification, inheritance, role, etc.) which are often confused or misused in modelling. Sometimes, this occurs because one kind of taxonomic hierarchy is used to represent two or more different concepts. In this paper we present a model of useful taxonomic hierarchies for conceptual modelling from an object-oriented perspective. The taxonomic hierarchies that we propose to represent knowledge are based on Aristotle?s definition of essence and accident.