Database Management System (DBMS): Computer Awareness
Database management system (DBMS) as the name suggests, is a tool that helps in organizing databases within our system by using various formats of representation. Database management system is a part of the syllabus of computer awareness in different banking examinations like IBPS RRB PO, IBPS RRB Clerk, and upcoming RBI Assistant & SBI Clerk. Having known the importance of database management system in various banking and other competitive examination, we are providing notes of the database management system that includes most important topics, methods and a guide to the database management system in a very easy and systematic way. The study notes on the database management system would be a complete preparation tool of the topic in the computer awareness section for the aspirants of RRB PO, RRB Clerk, RBI Assistant 2020 & SBI Clerk Mains 2020 exams.
What is a Database?
- A database is a collection of related data which represents some aspect of the real world. A database system is designed to be built and populated with data for a certain task.
What is DBMS?
- Database Management System (DBMS) is a software for storing and retrieving users’ data while considering appropriate security measures. It consists of a group of programs which manipulate the database. The DBMS accepts the request for data from an application and instructs the operating system to provide the specific data. In large systems, a DBMS helps users and other third-party software to store and retrieve data.
- DBMS allows users to create their own databases as per their requirement. The term “DBMS” includes the user of the database and other application programs. It provides an interface between the data and the software application.
History of DBMS
Here, are the important landmarks from the history:
- 1960 – Charles Bachman designed first DBMS system
- 1970 – Codd introduced IBM’S Information Management System (IMS)
- 1976- Peter Chen coined and defined the Entity-relationship model also know as the ER model
- 1980 – Relational Model becomes a widely accepted database component
- 1985– Object-oriented DBMS develops.
- 1990s– Incorporation of object-orientation in relational DBMS.
- 1991- Microsoft ships MS access, a personal DBMS and that displaces all other personal DBMS products.
- 1995: First Internet database applications
- 1997: XML applied to database processing. Many vendors begin to integrate XML into DBMS products.
Characteristics of Database Management System
- Provides security and removes redundancy
- Self-describing nature of a database system
- Insulation between programs and data abstraction
- Support of multiple views of the data
- Sharing of data and multiuser transaction processing
- DBMS allows entities and relations among them to form tables.
- It follows the ACID concept ( Atomicity, Consistency, Isolation, and Durability).
- DBMS supports multi-user environment that allows users to access and manipulate data in parallel.
Popular DBMS Software
Here, is the list of some popular DBMS system:
- Microsoft Access
- IBM DB2
- LibreOffice Base
- Microsoft SQL Server etc.
Four Types of DBMS systems are:
- Hierarchical database
- Network database
- Relational database
- Object-Oriented database
- In a Hierarchical database, model data is organized in a tree-like structure. Data is Stored Hierarchically (top down or bottom up) format. Data is represented using a parent-child relationship. In Hierarchical DBMS parent may have many children, but children have only one parent.
- The network database model allows each child to have multiple parents. It helps you to address the need to model more complex relationships like as the orders/parts many-to-many relationship. In this model, entities are organized in a graph which can be accessed through several paths.
- Relational DBMS is the most widely used DBMS model because it is one of the easiest. This model is based on normalizing data in the rows and columns of the tables. Relational model stored in fixed structures and manipulated using SQL.
- In Object-oriented Model data stored in the form of objects. The structure which is called classes which display data within it. It defines a database as a collection of objects which stores both data members values and operations.
Advantages of DBMS
- DBMS offers a variety of techniques to store & retrieve data
- DBMS serves as an efficient handler to balance the needs of multiple applications using the same data
- Uniform administration procedures for data
- Application programmers never exposed to details of data representation and storage.
- A DBMS uses various powerful functions to store and retrieve data efficiently.
- Offers Data Integrity and Security
- The DBMS implies integrity constraints to get a high level of protection against prohibited access to data.
- A DBMS schedules concurrent access to the data in such a manner that only one user can access the same data at a time
- Reduced Application Development Time
Disadvantage of DBMS
DBMS may offer plenty of advantages but, it has certain flaws-
- Cost of Hardware and Software of a DBMS is quite high which increases the budget of your organization.
- Most database management systems are often complex systems, so the training for users to use the DBMS is required.
- In some organizations, all data is integrated into a single database which can be damaged because of electric failure or database is corrupted on the storage media
- Use of the same program at a time by many users sometimes lead to the loss of some data.
- DBMS can’t perform sophisticated calculations.