• Unit 3: The History of Databases

    Databases have existed for centuries: the maintenance of records and data has evolved from engravings to cards to digital storage. The history of databases gives us a view of the evolution of database models and the problems of each model. Each subsequent model was motivated by the limitations of previous models, the availability of new technology, the need to store and retrieve new types of data, or by the need to handle new volumes of data that exceeded the capabilities of current models. In this unit, we will present the four different models of representing data, discussing the different limits of each.

    Completing this unit should take you approximately 3 hours.

    • Upon successful completion of this unit, you will be able to:

      • discuss the evolution of database technology and relate it to the evolution of computing; and
      • evaluate the four common data models relative to significant criteria for a selected application.

    • 3.1: Before Computers

      • Early databases were files that were a part of an application. As application data increased in size and complexity, databases became subsystems of applications. Though they contained information relevant for other applications, they had to be redesigned or re-implemented to integrate into those applications. Moreover, they often needed to be extended with other application data, such as enterprise data. These needs led to the design of a database as a common system that could be easily interfaced as a subsystem of many other applications. Database management systems were developed using different models that depended on the requirements of certain applications.

      • A Brief History of Databases Page

        This article makes several key points, and notes how the evolution of database technology reflects the evolution of how we model the world around us and is driven by the need to address the complexities that result from a proliferation of data. The growing demand for data and better data accessibility has led to a surge in the amount and quality of data available to people and organizations, databases have become so common that organizations are structured to reflect the model of their data.

      • History of Databases Page

        Watch this lecture, which gives an overview of the evolution of both traditional and non-traditional databases.

    • 3.2: The Four Revelations

      • Database Models Page

        This article defines explains some types of database models and describes data modeling in the context of the development of a database subsystem by focusing on its requirements, high level design, detailed design, and implementation. The first diagram depicts 5 categories of data models: flat files, early data models (network and tree), relational, and post-relational.

    • Unit 3 Assessment

      • Unit 3 Assessment Quiz
        Receive a grade

        Take this assessment to see how well you understood this unit.

        • This assessment does not count towards your grade. It is just for practice!
        • You will see the correct answers when you submit your answers. Use this to help you study for the final exam!
        • You can take this assessment as many times as you want, whenever you want.