33 research outputs found

    Online Data Modeling Tool to Improve Students\u27 Learning of Conceptual Data Modeling

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    Computer based instruction (CBI) has been used in science, mathematics, and engineering education, and showed positive outcomes. CBI is generally most effective when used as a supplement to traditional teaching. In this research-in-progress paper, the author presents an online data modeling tool as the supplement to data modeling teaching and proposes a research plan to measure students’ perceived effectiveness of the online tool

    A Web-Based Tool to Enhance Teaching/Learning Database Normalization

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    It has been difficult to motivate students to learn database normalization because students think the subject dry and theoretical. A web-based tool is developed to give students an interactive hands-on experience in database normalization process. The tool is suitable for relational data modeling in systems analysis and design and data management courses. This paper describes the web-based tool and its effectiveness in teaching relational data model. The effectiveness of the tool has been evaluated in surveys. The paper shows that the tool has a positive impact on students’ perception

    Ensuring the existence of a BCNF-decomposition that preserves functional dependencies in O (N2) time

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    A simple condition is presented that ensures that a relation scheme R with a set F of functional dependencies has a Boyce-Codd normal form (BCNF)-decomposition that has the lossless-join property and preserves functional dependencies

    Normalizing Database Normalization Definitions In AIS Text Books

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    Due to the abstract nature of the definitions for normal forms, over the years the interpretations of the definitions published in the textbooks, both MIS and AIS disciplines, have been differentiated and even deviated from its original form. The concept of deviation from the original form is a phenomenon that linguists call “semantic drift.” The most noticeable deviations are on first and second normal forms (i.e., 1NF and 2NF). Their definitions range from “atomic attribute” to “removing repeating group” for 1NF and from “functional dependency” to “removing partial dependency” in addition to being 1NF for 2NF. The purpose of this paper is to compare definitions of first, second, and third normal forms from the textbooks with those of the earlier forms and to identify shortfalls if there are any

    Dekompozicija relacijske sheme bez gubitka informacija

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    Postupkom normalizacije podataka relacijska shema dekomponira se na više manjih i pravilnijih podshema. Pomoću Rissanenovog kriterija nezavisnosti komponenata moguće je dokazati je li polazni skup informacija sačuvan, tj. da je dekompozicija početne relacijske sheme reverzibilna. Zahvaljujući tome Rissanenov test ima izvanrednu važnost u postupku oblikovanja baze podataka. Za Rissanenov test potrebno je imati komplet relacijskih shema koje se dobiju dekompozicijom, tj. potrebno je najprije izvršiti normalizaciju baze na relacijske sheme, a zatim izvršiti test. U radu se predlaže jedan novi test pomoću kojeg se može provjeriti reverzibilnost dekompozicije relacijske sheme bez da se prethodno izvršio postupak normalizacije
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