171,066 research outputs found

    A comparative analysis of data redundancy and execution time between relational and object oriented schema table

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    The design of database is one of the important parts in building software, because database is the data storage inside the system. There are some techniques that allow the programmer to improve design of the database. One of the most popular techniques being used for database is the relational technique, which content entity relationship diagram and normalization. The relational technique is easy to use and useful for reducing data redundancy because the normalization technique solves the data redundancy by applying normalization normal forms on the schema tables. The second technique is the object oriented technique, which content class diagram and generate schema table. An advantage of object oriented technique is its closeness to programming languages like C++ or C#. This project is starting with applying relational technique and object oriented technique to define which technique uses less data redundancy during design database. Based on experimental results for total data redundancy in HMS case study was 336 for relational technique and 364 for object oriented technique as well as, course database case study was 186 for relational technique and 204 for object oriented technique. Also, this project is focus on query execution time between relational databases and object oriented database by using user friendly window. The experimental result for query execution time in HMS case study was 107.25 milliseconds for RDBMS and 80.5 milliseconds for OODBMS. In course database case study was 46.75 milliseconds for RDBMS and 31.75 milliseconds for OODBMS. However, the comparative analysis in this project is explaining the result of comparison between relational and object oriented techniques specifically with data redundancy and query execution time

    Semi-automatic Database Design for Neuroscience Experiment Management Systems

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    Neuroinformatics provides tools for neuroscience researchers to study brain function. In order to handle experiment paradigms that change frequently, we are developing a semiautomatic database design tool that will enable an experiment management system (EMS) to manage data with flexibility while retaining the efficiency of a relational database

    The Consistency of Relational Database and Object-Relational Database in GIS Applications

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    This final year project involves a research and a simple Geographical Information System (GIS) application that will show GIS, spatial data, spatial database management, which focused on relational and object-relational database management system. The main objectives of this project is to study and gain deeper understanding on the implementation of the two types of databases in GIS applications, to compare the level of performance between the databases in a GIS application and to determine the most suggested database to be implemented in a GIS application. The scope of the study will focus on integrating a GIS application that implements Malacca spatial database with two different database management system, namely relational database and objectrelational database system. The performance of each database system will be identified and compared. Rapid Development environment methodology will be utilized in the research on the performance of relational and object-relational databases in GIS applications and also in the development of an application that will implement the database with GIS applications. This methodology basically involved overlapping Planning, Analysis, Design and Implementation phases. Database development design process involved conceptual, logical and physical design stages. This report also includes discussions on the consistency of relational database as well as of the objectrelational database in GIS applications. This report suggests GIS application developer to choose object-relational database in order to manage both spatial and attributes data for the applications efficiently. Furthermore, the result from the object-relational database will be more consistent and reliable compared to a relational database and the performance is better. Recommendations for continuing this project are to compare and determine the level of consistency between relational database and object-relational database in World Wide Web environment or with multi-user accessing the database concurrently in order to study on the effects to the level of consistency and also to develop a map query interface

    TOPYDE: A Tool for Physical Database Design

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    We describe a tool for physical database design based on a combination of theoretical and pragmatic approaches. The tool takes as input a relational schema, the workload defined on the schema, and some additional database characteristics and produces as output a physical schema. For the time being, the tool is tuned towards Ingres

    Teaching ORDB with UML Class Diagram in an Advanced Database Course

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    Object-relational database technology emerged as a way of enhancing object-oriented features in relational database management systems (RDBMSs). In response to this evolutionary change, the author has incorporated the technology into her advanced database course. This paper presents a teaching case on using UML (Unified Modeling Language) for object-relational database (ORDB) design and its implementation with Oracle. Course organization, course content, class activities, and impacts on the students\u27 learning outcomes are discussed. The paper is intended to provide a guide for database instructors who desire to incorporate object-relational technology and design in their traditional database courses

    Derived classes as a basis for views in UML/OCL data models

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    UML is the de facto standard language for analysis and design in object-oriented frameworks. Information systems, and in particular information systems based on databases and their applications, rely heavily on sound principles of analysis and design. Many present-day database applications employ object-oriented principles in the phases of analysis and design due to the advantages of expressiveness and clarity of such languages as UML. Database specifications often involve specifications of constraints, and the Object Constraint Language (OCL) - as part of UML - can aid in the unambiguous modelling of database constraints. One of the central notions in database modelling and in constraint specifications is the notion of a database view. A database view closely corresponds to the notion of derived class in UML. This paper will show how the notion of a derived class in UML can be given a precise semantics in terms of OCL. We will then demonstrate that the notion of a relational database view can be correctly expressed as a derived class in UML/OCL. A central part of our investigation concerns the generality of our manner of representing relational views in OCL. An important problem that we address in this respect is the representation of product spaces and relational joins. Joins are often essential in view definitions, and we shall demonstrate how we can express Cartesian products and joins within the current framework of UML/OCL language by employing the notions of derived class. As a consequence, OCL will be shown to be equipped with the full expressive power of the relational algebra, offering support for the claim that OCL can be useful as a general query language within the framework of the UML/OCL data model.

    UML Class Diagram or Entity Relationship Diagram : An Object Relational Impedance Mismatch

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    It is now nearly 30 years since Peter Chen’s watershed paper “The Entity-Relationship Model –towards a Unified View of Data”. [1] The entity relationship model and variations and extensions to ithave been taught in colleges and universities for many years. In his original paper Peter Chen looked at converting his new ER model to the then existing data structure diagrams for the Network model. In recent years there has been a tendency to use a Unified Modelling Language (UML) class diagram forconceptual modeling for relational databases, and several popular course text books use UMLnotation to some degree [2] [3]. However Object and Relational technology are based on different paradigms. In the paper we argue that the UML class diagram is more of a logical model (implementation specific). ER Diagrams on theother hand, are at a conceptual level of database design dealing with the main items and their relationships and not with implementation specific detail. UML focuses on OOAD (Object Oriented Analysis and Design) and is navigational and program dependent whereas the relational model is set based and exhibits data independence. The ER model provides a well-established set of mapping rules for mapping to a relational model. In this paper we look specifically at the areas which can cause problems for the novice databasedesigner due to this conceptual mismatch of two different paradigms. Firstly, transferring the mapping of a weak entity from an Entity Relationship model to UML and secondly the representation of structural constraints between objects. We look at the mixture of notations which students mistakenly use when modeling. This is often the result of different notations being used on different courses throughout their degree. Several of the popular text books at the moment use either a variation of ER,UML, or both for teaching database modeling. At the moment if a student picks up a text book they could be faced with either; one of the many ER variations, UML, UML and a variation of ER both covered separately, or UML and ER merged together. We regard this problem as a conceptual impedance mismatch. This problem is documented in [21] who have produced a catalogue of impedance mismatch problems between object-relational and relational paradigms. We regard the problems of using UML class diagrams for relational database design as a conceptual impedance mismatch as the Entity Relationship model does not have the structures in the model to deal with Object Oriented concepts Keywords: EERD, UML Class Diagram, Relational Database Design, Structural Constraints, relational and object database impedance mismatch. The ER model was originally put forward by Chen [1] and subsequently extensions have been added to add further semantics to the original model; mainly the concepts of specialisation, generalisation and aggregation. In this paper we refer to an Entity-Relationship model (ER) as the basic model and an extended or enhanced entity-relationship model (EER) as a model which includes the extra concepts. The ER and EER models are also often used to aid communication between the designer and the user at the requirements analysis stage. In this paper when we use the term “conceptual model” we mean a model that is not implementation specific.ISBN: 978-84-616-3847-5 3594Peer reviewe
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