The traditional approach to information processing has for a separate master file and its own set of personal files for each application. The major disadvantage of a file system is that files become dependent upon programs and in turn programs become dependent upon files. Few other concerns of a file-oriented approach are:
Data Redundancy: The same piece of information may be stored in two or more files. Since different programmers create the files and application programs over a long period, the various files are likely to have different formats and the programs may be written in several programming languages. Moreover, the same information may be duplicated in several files. The redundancy leads to higher storage and access costs and may lead to data inconsistency.
Difficulty in accessing data: The conventional file-processing environments do not allow the needed data to be retrieved in a convenient and efficient manner. So more responsive data retrieval systems are required for general use.
Data isolation: Since we have all the data scattered in various files and these files may be in different formats, retrieval of data in an appropriate format is difficult.
Integrity problems: The data values stored in the database must satisfy certain types of consistency constraints. The problem is compounded when constraints involve several data items from different files.
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