Here are the Exercise solutions for Chapter-2 Introduction to DBMS of IT Subject of Class 11 HSC Maharashtra Board 2021-22.
On this page, the theory questions answers have been explained for students reference particularly the “Answer the following segment”.
Solution for all Exercise questions has been given in the video below.
Q6. Answer the following Questions
1. What is a database?
The database is the collection of interrelated data which helps in efficient retrieval, inserting, and deleting of data. It enables user’s data to maintain in an organized manner it becomes meaningful or organized information.
It is a repository that is used to manage, define, construct and manipulate the data in the database for various applications.
2. What are the advantages of a DBMS?
Reducing Data Redundancy:–
This simply means data duplicate data that is present in various locations repeatedly. The file-based data management systems contained multiple files that were stored in many different locations in a system or even across multiple systems. Because of this, there were sometimes multiple copies of the same file which lead to data redundancy.
Sharing of Data:–
In a database, the users of the database can share the data among themselves. There are various levels of authorization to access the data, and consequently, the data can only be shared based on the correct authorization protocols being followed.
Data integrity means that the data is accurate and consistent in the database. Data Integrity is very important as there are multiple databases in a DBMS. All of these databases contain data that is visible to multiple users. So it is necessary to ensure that the data is correct and consistent in all the databases and for all the users.
Data Security is vital concept in a database. Only authorized users should be allowed to access the database and their identity should be authenticated using a username and password. Unauthorized users should not be allowed to access the database under any circumstances, as it violates the integrity constraints.
The privacy rule in a database means only authorized users can access a database according to its privacy
constraints. There are levels of database access and a user can only view the data.
For example – In social networking sites, access constraints are different for different accounts a user may want to access.
Backup and Recovery:-
Database Management System automatically takes care of backup and recovery. The users don’t need to backup data periodically because this is taken care of by the DBMS. Moreover, it also restores the database
after a crash or system failure to its previous condition.
Development and Maintenance Time:-
DBMS reduces application development and maintenance time. It supports many important functions that are common to many applications, accessing data stored in the DBMS, which facilitates the quick development of applications.
What do you understand by Data Model?
Data models define how the data is connected to each other and how they are processed and stored inside the system, including the retrieval, and updation in the database management system. Lastly, a data model is nothing but the logical structure of a database.
Relational Model:- It is the most popular data model in DBMS. The relational model is the primary data model, which is widely used for data storage and processing. This model is simple and has all the properties and capabilities required to process data with storage efficiency.
What is a primary key?
The group of one or more columns in a table whose values are used to uniquely identify each row of the table is called its Primary Key.
What is DDL(Data Definition Language)?
DDL statements or commands are used to define and modify the database structure of your tables or schema. When you execute a DDL statement, it takes effect immediately.
Apart from these questions, the rest have been answered in the above video “Exercise Solutions Introduction to DBMS Chapter 2 Class 11 HSC IT Maharashtra Board”.
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