Question 1

Question 1Assertion (A): Database management system is an application software which arranges data in a well-organized manner in the form of tables.Reasoning (R): DBMS acts as an interface between the database stored in the computer memory and the user.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationDatabase Management System (DBMS) is an application software that acts as an interface between the database stored in the computer memory and the user. It enables users to interact with the database and store data in a well-organized manner in the form of tables. The purpose of the DBMS software is to allow the user to create, access, modify, and control a database.

Question 2

Question 2Assertion (A): In hierarchical model, the data is organized in a tree-like structure.Reasoning (R): In hierarchical model, searching for a particular record is a time-consuming process.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationThe hierarchical model arranges data in a tree structure, where each record has a parent-child relationship. Searching for a specific record in such a model may require traversing through multiple levels of the hierarchy, which is time-consuming.

Question 3

Question 5Assertion (A): The number of attributes in a relation is called the degree of the relation.Reasoning (R): The number of tuples in a relation is called the cardinality of the relation.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true but R is not the correct explanation of A.ExplanationThe degree of a relation and the cardinality of a relation are two separate concepts in database management. The number of attributes or columns in a relation is called the degree of the relation, while the number of tuples or records in a relation is called the cardinality of the relation.

Question 4

Question 6Assertion (A): Each table must have one primary key.Reasoning (R): Primary key is a set of one or more attributes that uniquely identifies a tuple in a relation.Both A and R are true and R is the correct explanation of A.Both A and R are true but R is not the correct explanation of A.A is true but R is false.A is false but R is true.

Accepted Answer

Both A and R are true and R is the correct explanation of A.ExplanationIn a database, each table can have only one primary key, which is unique and non-redundant in nature. The primary key is a set of one or more attributes or fields that uniquely identify a tuple or row in a relation.

Question 5

Question 3What is the difference between data and information?

Accepted Answer

DataInformationData is the lowest level of abstraction.Information is one level higher abstraction than data.Data is unstructured and carries no meaning.Information is derived by interpreting and processing data.For example, marks such as 67, 88, 90 and 77 are considered data.For example, when these marks are related to a boy named Rohit, a student of class IX who has scored 67 in English, 88 in Maths, 90 in Physics and 77 in Chemistry then it becomes information.

Question 6

Question 4What is database and database system? What are the elements of database system?

Accepted Answer

Database is an organized collection of interpreted data that serves many applications.A Database Management System is a general-purpose software system that facilitates the process of defining, constructing and manipulating databases for various applications.A database system in SQL consists of tables with rows and columns, a schema defining structure and relationships, SQL for interaction, indexes for performance, constraints for data integrity.

Question 7

Question 7(a)Explain the difference between database and file.

Accepted Answer

DatabaseFileDatabase is an organized collection of interpreted data that serves many applications.A file is a collection of unorganized data stored in a single location.Data retrieval is fast and efficient, as databases use indexing and querying mechanisms.Data retrieval is slow and inefficient, as the entire file needs to be searched.Data sharing is easy, as multiple users and applications can access the database simultaneously.Data sharing is limited, as files are typically accessed by a single user or application.Data integrity is ensured through constraints, triggers, and transactions.Data integrity is not ensured, as data can be corrupted or lost easily.Databases support relationships between data entities.Files do not support relationships between data entities.

Question 8

Question 7(b)Explain the difference between data and file.

Accepted Answer

DataFileData refers to raw facts, figures, or values that are collected and stored without any specific context or interpretation.A file is a collection of unorganized data stored in a single location.The purpose of data is to convey information, provide insights, or support decision-making.The purpose of a file is to store, manage, and provide access to the data.Data can exist in various formats, such as numbers, text, images, or audio, and can be structured or unstructured.A file has a specific format and structure, defined by its file type (e.g., .txt, .jpg, .mp3), which determines how the data is stored and retrieved.

Question 9

Question 8Describe the components of the database system.

Accepted Answer

The various components of the database system are described below:Users — Users can be of varied types — Database administrators or DBAs, System or Application developers and end-users. DBMS provides the following critical services to the user :Database Creation — DBMS helps the user in creating and defining the required data or in turn, a database. It manages and organizes the required data and databases.Database Maintenance — A DBMS provides maintenance of data and database by addition, deletion, modification and regularly updating tables and their records.Database Processing — DBMS performs one of the major tasks of query processing — it processes the queries or the information requirement of the users and retrieves necessary information from the database.Database Application — Database applications may be personal, departmental, commercial and internal. It may be general-purpose or customized as per the needs of a user.DBMS — Software that allows users to define, create, access and manage databases is termed as a DBMS, for example, MySQL, Oracle, etc.Database — Database is an organized collection of logically related data.

Question 10

Question 9What are the advantages and disadvantages of DBMS?

Accepted Answer

The advantages of DBMS are as follows:Control of data redundancy — A DBMS eliminates data redundancy (duplication of data) by integrating the files so that multiple copies of the same data are not stored.Data consistency — DBMS provides data consistency to a large extent as the changes made at one place are reflected at all other places or to all the users.Sharing of data — Sharing of data using a DBMS implies that not only can the existing applications share the data in the database but also that new applications can be developed to operate against the same stored data.Reduced programming effort — A DBMS saves a lot of programming effort since a user need not write programs for query processing involving several tables or files, report generation, addition, modification and deletion of data, etc. Thus, it provides easy retrieval of data.Database enforces standards — With centralized control of the database, the DBA (Database Administrator) can ensure that all applicable standards are followed in the representation of data, i.e., format, documentation standards and conventions, etc.Improved data integrity — The system itself checks for the correct information to be entered by the user in the correct format.Privacy and Security — Since there is a centralized control, the data is protected.Economical — Combining all the organization's operational data into one database and creating a set of applications that works on this single source of data can result in cost saving. The overall maintenance cost of data is reduced.Improved backup and recovery system — A database system provides facilities for recovery from hardware or software failure.Solving enterprise requirement, not individual requirement — Since various types of users with varying levels of technical knowledge use a database, a DBMS should provide a variety of user interfaces.The disadvantages of DBMS are as follows:Complexity — DBMS software is complex and requires specialized knowledge to install, configure, and manage.Cost — Implementing and maintaining a DBMS involves high costs, including software licensing, hardware, and personnel.Maintenance — Regular maintenance, updates, and backups are required to ensure the DBMS operates efficiently and securely.

Question 11

Question 10What is the role of DBA?

Accepted Answer

The DBA or the Database Administrator is the person responsible for the security and functioning of the database.With centralized control of the database, the DBA (Database Administrator) can ensure that all applicable standards are followed in the representation of data, i.e., format, documentation standards and conventions, etc.

Question 12

Question 11What is data redundancy? How can it be controlled?

Accepted Answer

Repetition (duplication) of the same data in multiple files is known as data redundancy. A DBMS eliminates data redundancy by integrating the files so that multiple copies of the same data are not stored.

Question 13

Question 12What is data abstraction? What are the different levels of abstraction?

Accepted Answer

Data abstraction is a process of hiding the implementation details (such as how the data is stored and maintained) and representing only the essential features to simplify user's interaction with the system.The different levels of abstraction are:Physical/Internal levelLogical/Conceptual levelView level/External level

Question 14

Question 13What is data independence?

Accepted Answer

Data independence is the ability to change the schema at one level of a database system without requiring changes at a higher level. This is achieved through metadata, which follows a layered architecture, ensuring that changes to data at one layer do not affect data at another layer. A database system provides two types of data independence:Logical/Conceptual data independencePhysical data independence

Question 15

Question 14Give the terms for each of the following:(a) Collection of logically related records.(b) DBMS creates a file that contains description about the data stored in the database.(c) Attribute that can uniquely identify the tuples in a relation.(d) Special value that is stored when actual data value is unknown for an attribute.(e) An attribute which can uniquely identify tuples of the table but is not defined as primary key of the table.(f) Software that is used to create, manipulate and maintain a relational database.

Accepted Answer

(a) Table(b) Data dictionary(c) Primary key(d) NULL(e) Alternate Key(f) Database Management System (DBMS)

Source: This question is from Database Concepts, Informatics Practices &mdash; Class 11, CBSE Board.
Key Concepts CoveredThis question tests your understanding of the following concepts from the chapter Database Concepts: Question, Terms, Collection, Logically, Related, Records. These are fundamental topics in Informatics Practices that students are expected to master as part of the CBSE Class 11 curriculum.A thorough understanding of these concepts will help you answer similar questions confidently in your CBSE examinations. These topics are frequently tested in both objective and subjective sections of Informatics Practices papers. We recommend revising the relevant section of your textbook alongside practising these solved examples to build a strong foundation.
How to Approach This QuestionRead the question carefully and identify what is being asked. Break down complex questions into smaller parts. Use the terminology and concepts discussed in this chapter. Structure your answer logically — begin with a definition or key statement, then provide supporting details. Review your answer to ensure it addresses all parts of the question completely.
Key Points to RememberRead the question carefully and identify all parts before answering.
Use the terminology specific to this subject and chapter.
Review the textbook content for this chapter before attempting questions.
Practice writing concise, well-structured answers within time limits.
Related Questions from Database ConceptsQ1: Question 1 Assertion (A): Database management system is an application software which arranges data...
Q10: Question 9 What are the advantages and disadvantages of DBMS?
Q11: Question 10 What is the role of DBA?
Q12: Question 11 What is data redundancy? How can it be controlled?
Q13: Question 12 What is data abstraction? What are the different levels of abstraction?
Practice more questions from Database Concepts &mdash; Informatics Practices, Class 11 CBSE

Question 16

Question 15Why are foreign keys allowed to have NULL values? Explain with an example.

Accepted Answer

A null value can be entered in a foreign key, indicating that the records are not related. In certain situations, a foreign key may accept a NULL value if it's not a part of the primary key of the foreign table.For example, consider an Orders table in a database. Each order may or may not be associated with a customer. If an order is placed by a guest or a new customer who hasn't been added to the system yet, the CustomerID foreign key in the Orders table can be NULL to indicate that there is no associated customer record for that order.

Question 17

Question 16(a)Differentiate between database and table.

Accepted Answer

DatabaseTableDatabase is an organized collection of interrelated data that serves many applications.A table is a structure within a database that organizes data into rows and columns.It consists of multiple tables.It is comprised of rows and columns.It is at higher level in the data storage hierarchy.It is at lower level, as it is a component of the database.For example, MySQL database.For example, employee table.

Question 18

Question 16(b)Differentiate between primary key and foreign key.

Accepted Answer

Primary KeyForeign KeyPrimary Key is a column or group of columns in a table that uniquely identify every row in that table.A foreign key is an attribute whose value is derived from the primary key of another table. A foreign key is used to represent the relationship between two tables.Primary key cannot have Null values.Foreign key can have Null values.There can be only one primary key in a table.Multiple foreign keys can exist in a table.It is used to enforce entity integrity and ensure data uniqueness.It is used to enforce referential integrity and maintain data consistency across related tables.

Question 19

Question 16(c)Differentiate between degree and cardinality of a relation.

Accepted Answer

Degree of a relationCardinality of a relationThe number of attributes in a relation is called the Degree of the relation.The number of tuples in a relation is called the Cardinality of the relation.For example, if a relation has attributes like Name, Age, and Address, then its degree is 3.For example, if a relation contains 10 records or tuples, then its cardinality is 10.

Question 20

Question 17Compared to a file system, how does a database management system avoid redundancy in data through a database?

Accepted Answer

A database stores the data at a central location wherefrom all application programs can access data. This removes the need of saving own data by application program and thus it reduces data redundancy.

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