Controlling Data Redundancy
ADVANTAGES AND DISADVANTAGES OF DATABASE SYSTEMS
Advantages of Database Systems –
The DBMS (Database Management System) is preferred ever the conventional file processing system due to the following
1. Controlling Data Redundancy
In the conventional file processing system, every user group maintains its own files for handling its data files. This may lead to
• Duplication of same data in different files.
• Wastage of storage space, since duplicated data is stored.
• Errors may be generated due to updation of the same data in different files.
• Time in entering data again and again is wasted.
• Computer Resources are needlessly used.
• It is very difficult to combine information.
2. Elimination of Inconsistency
In the file processing system information is duplicated throughout the system. So changes made in one file may be necessary be carried over to another file. This may lead to inconsistent data. So we need to remove this duplication of data in multiple file to eliminate inconsistency.
To avoid the above problem, there is a need to have a centralize database in order to have this conflicting information.
On centralizing the data base the duplication will be controlled and hence inconsistency will be removed.
3. Better service to the users
A DBMS is often used to provide better services to the users. In conventional system, availability of information is often poor, since it normally difficult to obtain information in a timely manner because our existing systems are not capable to produce the same.
Once several conventional systems are combined to form one centralized database, the availability of information and its updateness is likely to improve since the data can now be shared and DBMS makes it easy to respond to anticipated information requests.
Centralizing the data in the database also means that user can obtain new and combined information easily that would have been impossible to obtain otherwise.
Also use of DBMS should allow users that don’t know programming to interact with the data more easily, unlike file processing system where the programmer may need to write new programs to meet every new demand.
4. Flexibility of the System is Improved
Since changes are often necessary to the contents of the data stored in any system, these changes are made more easily in a centralized database than in a conventional system.
Applications programs need not to be changed on changing the data in the database.
5. Integrity can be improved
Since data of the organization using database approach is centralized and would be used by a number of users at a time, it is essential to enforce integrity-constraints.
In the conventional systems because the data is duplicated in multiple files so updating or changes may sometimes lead to entry of incorrect data in some files wherever it is applicable.
Even if we centralized the database it may still contain incorrect data. For example: -• Salary of full time clerk may be entered as Rs. 1500 rather than Rs. 4500.
A student may be shown to have borrowed library books but has no enrollment.
The above problems can be avoided by defining the validation procedures whenever any update operation is attempted.
6. Standards can be enforced
Standards are easier to enforce in database systems because all the data in database is access through centralized DBMS.
Here standards may relate to the naming of data, structure of data, format of the data etc.
Standardizing stored data formats is usually desirable for the purpose of data interchange or migration between systems.
7. Security can be improved
In conventional systems, applications are developed in an adhoc manner.
Often different system of an organization would access different components of the operational data, in such an environment enforcing security can be quiet difficult.
Setting up of a database makes it easier to enforce security restrictions since data is now centralized.
It is easier to control who has access to what parts of the database. Different checks can be established for each type of access (retrieve, modify, delete etc.) to each piece of information in the database.
8. Organization’s requirement can be easily identified
All organizations have sections and departments and each of these units often consider the work of their unit as the most important and therefore consider their need as the most important.
Once a database has been setup with centralized control, it will be necessary to identify organization’s requirement and to balance the needs of the competition units.
So it may become necessary to ignore some requests for information if they conflict with higher priority need of the organization.
9. Data Model must be developed
Perhaps the most important advantage of setting up of database system is the requirement that an overall data model for an organization be build. In conventional systems, it is more likely that files will be designed as per need of particular applications demand.
The overall view is often not considered. Building an overall view of an organization’s data is usual cost effective in the long terms.
10. Provides backup and Recovery
Centralizing a database provides the schemes such as recovery and backups from the failures including disk crash, power failures, software errors which may help the database
to recover from the inconsistent state to the state that existed prior to the occurrence of the failure, though methods are very complex.
Disadvantages of Database Systems
The following are the disadvantages of Database Systems
1. Database Complexity
The design of the database system is complex, difficult and is very time consuming task to perform.
2. Substantial hardware and software start-up costs Huge amount of investment is needed to setup the required hardware and the softwares needed to run those applications.
3. Damage to database affects virtually all applications programs If one part of the database is corrupted or damaged because of the hardware or software failure, since we don’t have many versions of the file, all the application programs which are dependent on this database are implicitly affected.
4. Extensive conversion costs in moving form a file-based system to a database system If you are currently working on file based system and need to upgrade it to database system, then large amount of cost is incurred in purchasing different tools, adopting different techniques as per the requirement.
5. Initial training required for all programmers and user. Large amount of human efforts, the time and cost is needed to train the end users and application programmers in order to get used to the database systems.
Posted By-: Vissicomp Technology Pvt. Ltd.
Website -: http://www.vissicomp.com