Papers by Mohamed Mkaouar
Abstract: To guarantee a complete data history in temporal databases, database management systems... more Abstract: To guarantee a complete data history in temporal databases, database management systems have to manage both evolution of schema over time, through their versioning, and evolution of data defined under different schema versions. This paper proposes a new approach for schema versioning in multi-temporal databases. It allows an efficient management of schema versions and their underlying data, through a smooth conversion of the temporal database. When creating a new schema version, the basic idea consists in forbidding (i) any automatic transfer of data defined under previous schema versions to this new version, in order to avoid data loss and ambiguousness in the interpretation of temporal intervals of data, and (ii) any change in the structures of previous schema versions, in order to permit to the legacy applications to remain operational after this schema evolution.
Techniques et sciences informatiques, 2007
ABSTRACT. The effective design and implementation of applications based on Temporal DataBases (TD... more ABSTRACT. The effective design and implementation of applications based on Temporal DataBases (TDB) require the introduction of new concepts pertinent to "temporal fact" (fact associated to time values) modeling, starting from the conceptual level. Since UML (Unified Modeling Language) is the most standard used to analyze and model information systems, we propose in this paper an UML profile, entitled UML-TF (an UML profile for Temporal Facts), that allows the representation of temporal facts at both the conceptual and organizational levels. One of the main advantages of UML-TF is its capacity to represent such facts through concepts at the conceptual level (temporal attributes, temporal classes, temporal associations, etc.) in a simple, rigorous and expressive manner. This UML-TF advantage is illustrated through examples of concrete applications.
Applications requiring a full and efficient management of data feel the need to consider, beside ... more Applications requiring a full and efficient management of data feel the need to consider, beside the current facts, historical and future facts, and to keep the track of the manipulation of facts by the DBMS. In this paper, we define concepts and modeling tools to express constraints, taking into account the temporal dimension. The expression of these constraints is achieved through an independent platform modeling, in the UML-TF profile. Next, we propose extensions to the SQL3 to be able to convert enhanced UML-TF representations in a specific object-relational platform.
Dans cet article, nous proposons une approche pour l'extension d'un SGBD Relationnel perm... more Dans cet article, nous proposons une approche pour l'extension d'un SGBD Relationnel permettant une manipulation aisée des faits temporels, c'est-à-dire des faits associés à des valeurs de temps. Cette approche consiste en la définition de framework, constitué de fonctionnalités temporelles, qui dispense le développeur de l'écriture de requêtes complexes. Il devient ainsi possible de construire des formulaires permettant aux utilisateurs de mettre à jour et d'interroger des faits temporels d'une manière simple et confortable. Summary: In this paper, we propose an approach for the extension of a Relational DBMS to easy manipulate temporal facts, i.e. facts associated to time values. Our approach consists in the definition of a framework, composed of temporal functionalities, which dispenses the developer for writing complex queries. So, it becomes possible to construct forms that allow users updating and querying temporal facts in a simple and comfortable manner.
The methodological integration of the temporal dimension in databases requires primitives that al... more The methodological integration of the temporal dimension in databases requires primitives that allow rigorous and progressive specification of this dimension since the conceptual and organizational levels. For this goal, we propose concepts and graphic formalisms, in accordance with the abstractions of the tow levels of the entity-relationship model. These concepts allow the expression of requirements of atomic, local and global histories, through valid-time, transaction-time or bitemporal component-types (property-type, entity-type, etc.). The application of these concepts to the MERISE/2 method gave the MERISE/TEMPO extension. Illustrative examples of the proposed component-types, drawn of an experimentation of a concrete application, are given. MOTS-CLÉS : Bases de Données Temporelles, Extension Temporelle, Modèle Entité-Relation, Modélisation.
Many works have focused, for over twenty five years, on the integration of the time dimension in ... more Many works have focused, for over twenty five years, on the integration of the time dimension in databases (DB). However, the standard SQL3 does not yet allow easy definition, manipulation and querying of temporal DBs. In this paper, we study how we can simplify querying and manipulating temporal facts in SQL3, using a model that integrates time in a native manner. To do this, we propose new keywords and syntax to define different temporal versions for many relational operators and functions used in SQL. It then becomes possible to perform various queries and updates appropriate to temporal facts. We illustrate the use of these proposals on many examples from a real application.
Techniques et sciences informatiques, 2016
Tsi Technique Et Science Informatiques, 2007
Mohamed Mkaouar Équipe EBDA, Tunisie. [email protected] Rafik Bouaziz LIP2 – EBDA : Fa... more Mohamed Mkaouar Équipe EBDA, Tunisie. [email protected] Rafik Bouaziz LIP2 – EBDA : Faculté des Sciences Économiques et de Gestion de Sfax. [email protected] RÉSUMÉ : Les SGBD actuels n'offrent pas d'outils appropriés pour l'implémentation et la manipulation des Bases de Données Temporelles (BDT). Or, le développement ad hoc des applications utilisant des données temporelles s'avère difficile et coûteux. C'est que ce développement requiert de nouvelles fonctionnalités que le SGBD doit offrir. Les outils que nous proposons dans ce papier se situent dans ce cadre ; ils étendent SQL* Forms d'Oracle par une couche comportant des fonctions réutilisables pour manipuler des requêtes temporelles dynamiques et des outils graphiques pour gérer les valeurs de temps et interroger l'historique des faits.
Dans cet article, nous proposons une approche pour l'extension d'un SGBD Relationnel permettant u... more Dans cet article, nous proposons une approche pour l'extension d'un SGBD Relationnel permettant une manipulation aisée des faits temporels, c'est-à-dire des faits associés à des valeurs de temps. Cette approche consiste en la définition de framework, constitué de fonctionnalités temporelles, qui dispense le développeur de l'écriture de requêtes complexes. Il devient ainsi possible de construire des formulaires permettant aux utilisateurs de mettre à jour et d'interroger des faits temporels d'une manière simple et confortable.
Manar II, Tunis -Tunisie. [email protected] RÉSUMÉ. L'intégration méthodologique de la di... more Manar II, Tunis -Tunisie. [email protected] RÉSUMÉ. L'intégration méthodologique de la dimension temporelle dans les bases de données exige que l'on dispose des primitives qui permettent une spécification rigoureuse et progressive de cette dimension dès les niveaux conceptuel et organisationnel. Dans ce but, nous proposons un ensemble de concepts et de formalismes graphiques, conformes aux abstractions fixées pour les deux niveaux du modèle entité-relation. Ces concepts permettent d'exprimer des besoins en historiques atomiques, locaux et globaux, à travers des composants-types (propriété-type, entité-type, etc.) temporels de validité, des composantstypes temporels de transaction ou des composants-types bitemporels. L'application de ces concepts à la variante MERISE/2 a donné lieu à une extension intitulée MERISE/TEMPO. Des exemples illustratifs des constructions-types proposées sont donnés, tirés d'une expérimentation sur une application concrète.
Computing Research Repository, 2011
Many works have focused, for over twenty five years, on the integration of the time dimension in ... more Many works have focused, for over twenty five years, on the integration of the time dimension in databases (DB). However, the standard SQL3 does not yet allow easy definition, manipulation and querying of temporal DBs. In this paper, we study how we can simplify querying and manipulating temporal facts in SQL3, using a model that integrates time in a native manner. To do this, we propose new keywords and syntax to define different temporal versions for many relational operators and functions used in SQL. It then becomes possible to perform various queries and updates appropriate to temporal facts. We illustrate the use of these proposals on many examples from a real application.
Summary form only given. Relational model lacks the support for a standard approach to manipulate... more Summary form only given. Relational model lacks the support for a standard approach to manipulate the temporal dimension of data. The development of temporal applications through this model is therefore complex and expensive, especially since it is realized in an ad hoc manner. On the other hand, designers now require simple, rapid and efficient development tools. This motivated our interest in enriching relational model-based development environments in order to improve the fruitfulness of development. We propose the development process and a new support toolset to manipulate time values and manage temporal databases. The proposed toolset is realized as an extension of the oracle forms tool.
does not yet allow easy definition, manipulation and querying of temporal DBs. In this paper, we ... more does not yet allow easy definition, manipulation and querying of temporal DBs. In this paper, we study how we can simplify querying and manipulating temporal facts in SQL3, using a model that integrates time in a native manner. To do this, we propose new keywords and syntax to define different temporal versions for many relational operators and functions used in SQL. It then becomes possible to perform various queries and updates appropriate to temporal facts. We illustrate the use of these proposals on many examples from a real application.
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Papers by Mohamed Mkaouar