The Advantages Of Database Management Systems Information Technology Essay
Database Management systems serve many roles that provide the DBMS users with advantages over file systems and other systems that support data management. List some of these advantages and provide an example, either generic or specific, of each. There is a list in section 1.3.1 of the RobCor 9 textbook to get you started. Feel free to extend this list or to categorize the advantages differently.
Improve Data Sharing: DBMS helps create as environment where end-user has better access to more and better managed data. In conventional system, availability of information is often poor, since it normally difficult to obtain information that the existing systems were not designed for.
Once centralised database is in place, the information will be more updated since the data can now be shared and DBMS makes it easy to respond to anticipated queries.
Also users with less programming knowledgecan now interact with the data more easily, unlike the conventional system.
Improved Data Security: In any organisation, no of users accessing the data increases, risk of data security breaches also increases. DBMS provides better framework with better data privacy and security policies.
Example of banking in which the employee at different levels may be given access to different types of data in the database. A clerk may be given the authority to know only the names of all the customers who have a loan in bank but not the details of each loan the customer may have. It can be accomplished by giving the privileges to each employee.
Better Data Integration: Wider access to well-managed data promotes an integrated view of the organisation’s operation and clear view of bigger picture.
For example in conventional system since multiple files are maintained, we may enter value of field which may not exists. Suppose Courses can have values (Computer, Accounts, Economics, and Arts) but we enter a value ‘Hindi’ for it, which is inconsistency, so lack of Integrity.
Minimise Data Inconsistency: When different versions of same data appear in different places, it is data consistency.
Suppose that in STUDENT file it is indicated that Roll no= 10 has opted for ‘Computer’course but in RESULT file it is indicated that ‘Roll No. =l0’ has opted for ‘Accounts’ course. Thus, in this case the two entries for particular student don’t agree with each other. Thus, database is said to be in an inconsistent state.
Probablity of data inconsistency is greatly reduced in properly designed database.
Controlling Data Redandancy: 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, Time in entering data again and again is wasted, It is very difficult to combine information.
All these can be reduced with properly designed database.
Improve Decision Making: In any organization, better managed data and improved data access make it possible to generate quality information, on which better decisions can be made. The quality of information generated is depend on quality od underlying data. While DBMS does not guarantee data quality, it comes with better framework to facilitate data quality initiatives.
For Example A DBA must choose best file Structure and access method to give fast response for the high critical applications as compared to less critical applications.
Increase End user Productivity: Better managed data, along with the tools that transform data in usable information provides end user with better quality data, empowers end user to make decisions, informed decisions that can make the differencebetween success and failure in global economy.
For example, A CEO would like to have better picture about his financial data to make out about profit and loss equations.
Cost of Devlopement and Maintaining the system is low: It is much easier to respond to unanticipated requests when data is centralized in a database. Although the initial cost of setting up of a database can be large, one normal expects the overall cost of setting up of a database, developing and maintaining application programs to be far lower than for similar service using conventional systems, Since the productivity of programmers can be higher in using non-procedural languages that have been developed with DBMS than using procedural languages.
Provide Backups 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.
Topic 2: Structural Independence
Database systems exhibit structural independence, which occurs when the way that applications and users operate with the database is independent of how the data is actually stored in the file system or other storage device. Explain why structural independence is important to people who develop and maintain database applications and to database users.
Structural independence exists when it is possible to make changes in the file structure without effecting the application program’s ability to access the data.
The practicle significanse of data deoendance is difference between logical data format and physical data format. Any program that access file system must tell computer not only what to do but also how to do it. Consequently, each program must contains lines that specify the opening of specific file type, its record specifications and its fields definitions.
In conventional file system, Adding a field to a file would require to Read a record from original file, transform original data in new structure requirements and again writes transform data in new structure. Thus, all of file system should be modified to accommodate new file structure, showing its structural dependance.
We can avoid this with properly designed database system.
Topic 3: Problems with Data Redundancy
Data redundancy occurs when the same data is duplicated in different parts of a data management system in such a way that the duplicates are unnecessary and the duplicates can become inconsistent. Describe one or more situations in which data redundancy in a database system can cause problems. It is OK to describe situations from your own experience, either with databases or with other data management systems.
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, Time in entering data again and again is wasted, It is very difficult to combine information.
For Example, In file system, The entire Finance department would share access to finance data files. With the use of spreadsheets, each and every member of finance department may create their own copy of finance data. Since it is unlikely that data stired in different location is getting updated consistently, they often contain different versions of same data.
Customer contact information will be preent in both Customer and Agents files. So, we need only one correct copy of customer’s contact information. But since they are presene in different locations, it is data redundancy.
Topic 4: Five Major Components of a DBMS
Our Rob and Coronel text describes database systems as having five major components: hardware, software, people, procedures, and data. Describe ways in which people interact with and are responsible for hardware, software, procedures, and data in a database system environment. You don’t need to try to provide an exhaustive list, because that would be voluminous, but only an indication that you have thought about how people are responsible for and interact with each of the other four components.
Suppose in a local movie rental shop uses a software which will maintain and keep track about the DVDs rented and returned by customer. It will contain information about customer data, new DVD information, rental for each DVD, type of movie.
When the operator uses this system, he or she may be using a PC or Laptop as hardware device. Procedure, instructions and rules that governs the use of database system, will be simple. Operator will follow the steps to check the information or to make any changes in data. For that, operator will use a simple DBMS software which will make sure everything is in place along with Operating System and some other utilities, which will take care of data.