Managing Information Systems In Organizations
In recent years, there has been an abundance of new technologies in the information systems field. These new technologies have altered the very development process itself. Information systems have gone from being a series of one level databases to three dimensional reality, virtual reality, and multimedia systems. In the early days of information systems, the demands were for data, with no real function of artificial intelligence. However, as the 21st century approaches, business has taken on an entirely different function, and the need for individual information systems has grown immensely. This demand for information technology is in all areas of business: corporations, law, medicine, science and even small business. In addition, the worldwide web and the Internet have added an additional factor of communications. Most information systems in use today require at the very least, a measure of Internet capability.
In order to understand the changes in these development processes, the history of databases should be analyzed.
Database Management Systems actually began in the 1950s, with what is known as the first generation, also known as file systems on tape. The major task of any computer in those days was to process data under the control of a program. This primarily meant calculating, counting and simple tasks. Second generation databases, file systems on disk, allowed use of computers in dialogue mode as well as batch mode. The development of magnetic disks allowed for more sophisticated file systems, making multiple access possible. These first two generations of DBMS were characterized by the availability of file systems only; strictly speaking these were the forerunners of database systems, the foundations. An important component of these database systems were the static association of certain data sets (files) with individual programs that would concentrate on these. There were high redundancy problems between files; inconsistencies when one program made changes that are not made in all programs; inflexibility against changes in applications; low productivity by programmers since program maintenance was expensive; and the problem of adopting and maintaining standards for coding and data formats.
The third generation, pre-relational databases, started in the 1960s and continued into the 1970s. This generation is characterized by the introduction of a distinction between logical and physical information, along with a parallel need to manage large collections of data. Data models were used for the first time to describe physical structures from a logical point of view. With this distinction between the logical and physical information, value systems were developed which could integrate all the data of a given application into one collection.
The fourth generation consisted of relational databases and began in the 1980s, resulting in database systems...