06 September 2009

A Brief History of Database Applications

    1. Early Database Applications Using Hierarchical and Network Systems: Many early database applications maintained records in large organzations, such as corporations, universities, hospitals, and banks. In many of these applications, there were large numbers of records of similar structure. One of the main problems with early database systems was the intermixing of conceptual relationships with the physical storage and placement of records on disk. Another shortcoming of early systems was that they provided only programming language interfaces. This made it time-consuming and expensive to implement new queries and transactions, since new programs had to be written, tested, and debugged.
    2. Providing Application Flexibility with Relational Databases : Relational databases were originally proposed to separate the physical storage of data from its conceptual representation and to provide a mathematical foundation for databases. The relational data model also introduced high-level query languages that provided an alternative to programming language interfaces; hence, it was a lot quicker to write new queries. Eventually, relational databases became the dominant type of database systems for traditional database applications. Relational databases now exist on almost all types of computers, from small personal computers to large servers.
    3. Object-Oriented Applications and the Need for More Complex Databases : The emergence of object-oriented programming languages in the 1980s and the need to store and share complex-structured objects led to the development of object-oriented databases. Initially, they were considered a competitor to relational databases, since they provided more general data structures. They also incorporated many of the useful object oriented paradigms, such as abstract data types, encapsulation of operations, inheritance, and object identity. However, the complexity of the model and the lack of an early standard contributed to their limited usc. They are now mainly used in specialized applications, such as engineering design, multimedia publishing, and manufacturing systems.
    4. Interchanging Data on the Web for E-Commerce : The World Wide Web provided a large network of interconnected computers. Users can create documents using a Web publishing language, such as HTML (HyperText Markup Language), and store these documents on Web servers where other users (clients) can access them. Documents can be linked together through hvpcrlinks, which are pointers to other documents. A variety of techniques were developed to allow the interchange of data on the Web. Currently, XML (eXtended Markup Language) is considered to be the primary standard for interchanging data among various types of databases and Web pages. XML combines concepts from the models used in document systems with database modeling concepts.
    5. Extending Database Capabilities for New Applications : The success of database systems in traditional applications encouraged developers of other types of applications to attempt to use them. Such applications traditionally used their own specialized file and data structures.

    2 comments:

    1. i copied this for my assignment. thanks

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    2. nice post..visit this for full notes of computer science engineering...http://dbmsenotes.blogspot.in/

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