A database refers to a collection of related data and a Database System is basically a computer based record keeping system. A database system is basically contains information about the one particular enterprise. It maintains any information that may be necessary to the Decision-Making Process involved in the management of that organization.
The intentions of a database are that the same collation of a data should serve as much application as possible. Hence a database is often conceived of as much application as possible. Hence a database is often conceived of as the repository of information needed for running certain function in certain corporation or organization. Such as data base world print not only the related data but also the continuous modification of data needed for control of operations.
This chapter is going to discuss the basis of Database and Their Functioning. This discussion will lay foundation of MS Access learning for you.
In atypical File Processing System, permanent records are stored in various files. A number of different application programs are written to extract records form and records to appropriate files. But this scheme has (duplication of data) data inconsistency, unshakable data, un-standardized data, insecure data; etc .A database management system is answer to all these problems as it provides centralized control of data.
For instance, in a residential school, if two files are being maintained –one for school and another for hostel – it might create problems. As for the students who live in hostel, their records are stored in two separate files – School Files and Hostel Files. Now consider a situation in which a hostel informs the school authority as well as the hostler authority about the change of this correspondence address. What will happen, if the school authority forget to change the student’s address but hostel file is modified with change address? There are two addresses pertaining to same student. Such a situation is called data inconsistency, and this arises because the same data is stored in multiple places separately. Similar type of other problems can also be occurring is data is replicated or not stored properly.
Database system does not maintain separate copies of the same data. Rather all the data are kept at one place and all the application that require data refer to the centrally maintained database (Collection of Data). Now if any changes are to be made to data, it will be made at just one place and the same changed information will be available to all the application referring to it. We do not mean to suggest that redundancy should necessarily to be eliminated. Sometimes there is sound business of technical reason for maintaining multiple copies of the same data. In a database system however, redundancy can be controlled up to the desired extent and the system is aware of the redundancy, if any.
Data redundancy means duplication of data. On-Database System maintains separate copy of data for each application. For e.g. In a college student records maintained. And the hostel also maintains for all those college students who lives in hostel.
This is really corollary of the previous point. When the redundancy is not controlled there may be occasions on which the two entries about the same data do not agree (that is, one of them stores the updated information and others are not). At such times database is said to be inconsistency. Obviously, an inconsistent database will provide incorrect or Conflicting Information.
Sharing of data means that providing the individual pieces of data in the database may be shared among several different, in the sense that each of those users may have access to the same pieces of data and each of them may use of different purpose.
The database management system can ensure that all the data follow the applicable standards. They may be standard certain lay by the company or Organization Using The Database. Or there may be certain industry standard that must be satisfied by the data similarly, there may be national or international standard.
The information stored inside a database is sometime of great value to a corporation. Therefore, it must be kept secure and private.
A database management system ensure data security and privacy by ensuring the only means of access to the database is through the proper channel and also by carrying out authorization checks whenever access to sensitive data is attempted.