Why is DBMS required ? ( 5 marker )
Answers
Answer:
A database management system is important because it manages data efficiently and allows users to perform multiple tasks with ease. A database management system stores, organizes and manages a large amount of information within a single software application. Use of this system increases efficiency of business operations and reduces overall costs.
Database management systems are important to businesses and organizations because they provide a highly efficient method for handling multiple types of data. Some of the data that are easily managed with this type of system include: employee records, student information, payroll, accounting, project management, inventory and library books. These systems are built to be extremely versatile.
hope it will help u
Answer:
Importance of DBMS
A database management system is important because it manages data efficiently and allows users to perform multiple tasks with ease. A database management system stores, organises and manages a large amount of information within a single software application.
1) Processing Queries and Object Management:
In traditional file systems, we cannot store data in the form of objects. In practical-world applications, data is stored in objects and not files. So in a file system, some application software maps the data stored in files to objects so that can be used further.
We can directly store data in the form of objects in a database management system. Application level code needs to be written to handle, store and scan through the data in a file system whereas a DBMS gives us the ability to query the database.
2) Controlling redundancy and inconsistency:
Redundancy refers to repeated instances of the same data. A database system provides redundancy control whereas in a file system, same data may be stored multiple times. For example, if a student is studying two different educational programs in the same college, say ,Engineering and History, then his information such as the phone number and address may be stored multiple times, once in Engineering dept and the other in History dept. Therefore, it increases time taken to access and store data. This may also lead to inconsistent data states in both places. A DBMS uses data normalization to avoid redundancy and duplicates.
3) Efficient memory management and indexing:
DBMS makes complex memory management easy to handle. In file systems, files are indexed in place of objects so query operations require entire file scans whereas in a DBMS , object indexing takes place efficiently through database schema based on any attribute of the data or a data-property. This helps in fast retrieval of data based on the indexed attribute.
4) Concurrency control and transaction management:
Several applications allow user to simultaneously access data. This may lead to inconsistency in data in case files are used. Consider two withdrawal transactions X and Y in which an amount of 100 and 200 is withdrawn from an account A initially containing 1000. Now since these transactions are taking place simultaneously, different transactions may update the account differently. X reads 1000, debits 100, updates the account A to 900, whereas Y also reads 1000, debits 200, updates A to 800. In both cases account A has wrong information. This results in data inconsistency. A DBMS provides mechanisms to deal with this kind of data inconsistency while allowing users to access data concurrently. A DBMS implements ACID(atomicity, durability, isolation,consistency) properties to ensure efficient transaction management without data corruption.
5) Access Control and ease in accessing data:
A DBMS can grant access to various users and determine which part and how much of the data can they access from the database thus removing redundancy. Otherwise in file system, separate files have to be created for each user containing the amount of data that they can access. Moreover, if a user has to extract specific data, then he needs a code/application to process that task in case of file system, e.g. Suppose a manager needs a list of all employees having salary greater than X. Then we need to write business logic for the same in case data is stored in files. In case of DBMS, it provides easy access of data through queries, (e.g., SELECT queries) and whole logic need not be rewritten. Users can specify exactly what they want to extract out of the data.