15 extra multiple-choice questions for Introduction to Database Management System (12th Standard Computer Applications, Samacheer Kalvi), beyond the ones printed in the textbook — each with the correct option highlighted and a clear, worked explanation. Free to read in English and Tamil.
Q1
Which database model represents records in a tree-like structure with a parent-child relationship?
- A. Relational model
- B. Network model
- C. Hierarchical database modelCorrect
- D. Object-oriented model
Explanation. In a hierarchical database model, such as IBM IMS, records are organized in a parent-child relationship resembling a tree structure.
Q2
In the ACID properties of a database, which property ensures that all updates in a transaction are completed successfully, or none of them are applied at all?
- A. AtomicityCorrect
- B. Consistency
- C. Isolation
- D. Durability
Explanation. Atomicity follows the All or Nothing rule, ensuring that a database transaction either completely commits or aborts entirely.
Q3
Which administrative MySQL command must be executed after creating a new user account to update the privileges in the server without manual server rebooting?
- A. RESET PRIVILEGES;
- B. FLUSH PRIVILEGES;Correct
- C. RELOAD PRIVILEGES;
- D. UPDATE PRIVILEGES;
Explanation. The FLUSH PRIVILEGES command updates user account privileges on the server, serving a function similar to rebooting the server.
Q4
What is a candidate key that has not been selected as the primary key of a relation called?
- A. Alternate keyCorrect
- B. Composite key
- C. Foreign key
- D. Super key
Explanation. The candidate key that is chosen for unique row identification is the primary key, and any other candidate keys are alternate keys.
Q5
In an Entity-Relationship (ER) model, which type of attribute is represented by a double ellipse?
- A. Simple attribute
- B. Composite attribute
- C. Single valued attribute
- D. Multivalued attributeCorrect
Explanation. In ER diagram notation, multivalued attributes are represented by double ellipses.
Q6
Which of the following SQL commands is classified under Data Definition Language (DDL)?
- A. INSERT
- B. UPDATE
- C. TRUNCATECorrect
- D. DELETE
Explanation. TRUNCATE is a DDL command used to delete all table records. INSERT, UPDATE, and DELETE are Data Manipulation Language commands.
Q7
Under which category of SQL commands do COMMIT, ROLLBACK, and SAVEPOINT fall?
- A. Data Definition Language (DDL)
- B. Data Control Language (DCL)
- C. Transaction Control Language (TCL)Correct
- D. Data Manipulation Language (DML)
Explanation. Transaction Control Language commands manage database transactions and help to save or undo changes permanently.
Q8
What is the SQL standard version referenced in the provided introduction to MySQL?
- A. 1986
- B. 1987
- C. 1999
- D. 2003Correct
Explanation. The SQL standard always refers to the current version, and according to the textbook, the current version is 2003.
Q9
Which database model combines Object-Oriented Programming (OOP) concepts with database technologies and serves as the practical base of the relational model?
- A. Hierarchical database model
- B. Object-oriented database modelCorrect
- C. Network model
- D. Relational model
Explanation. The object-oriented database model incorporates OOP concepts with database technologies and practically serves as the base of the relational model.
Q10
Which administrative desktop application tool is specifically designed for developers and DBAs to help with visualization, data modeling, server configuration, and backups?
- A. phpMyAdmin
- B. HeidiSQL
- C. MySQL WorkbenchCorrect
- D. SQLite
Explanation. MySQL Workbench is a desktop application tool used mainly for visualization, data modeling, SQL development, server configuration, and backups.
Q11
What is the degree of a relationship that connects one entity type to itself in a loop?
- A. UnaryCorrect
- B. Binary
- C. Ternary
- D. N-ary
Explanation. The number of entity types involved determines the degree. A relationship connecting an entity to itself is unary.
Q12
Which property of a foreign key allows it to represent a relationship, but differs from a primary key's default behavior?
- A. It must always have unique values
- B. Its values do not usually have to be unique and can be nullCorrect
- C. It cannot contain composite attributes
- D. It must never reference another table's primary key
Explanation. Unlike primary keys, foreign key values do not usually have to be unique, and they are allowed to contain null values.
Q13
Which of the following is a minimal super key with no redundant attributes?
- A. Primary key
- B. Alternate key
- C. Candidate keyCorrect
- D. Composite key
Explanation. Candidate keys are selected from the set of super keys by removing redundant attributes, making them minimal super keys.
Q14
Which administrative command is used by a DBA to get a detailed report on the performance of a specific table in MySQL?
- A. SHOW INDEX FROM tablename;
- B. SHOW COLUMNS FROM tablename;
- C. SHOW TABLE STATUS LIKE tablename\GCorrect
- D. SHOW TABLES;
Explanation. The command SHOW TABLE STATUS LIKE tablename\G provides a detailed performance report for the specified table.
Q15
Which database model is similar to the hierarchical model but allows each member to have more than one owner, handling many-to-many relationships better?
- A. Network modelCorrect
- B. Relational model
- C. Object-oriented model
- D. Flat model
Explanation. The network model is similar to the hierarchical model, but each member can have more than one owner to handle many-to-many relationships.
Frequently asked questions
How many MCQs are there in Introduction to Database Management System?
This chapter has 15 book-back multiple-choice questions, each with the correct answer and a step-by-step explanation.
Are these 12th Standard Computer Applications MCQs free to practise online?
Yes. Every question, answer and explanation here is free, and you can also take them as a timed practice test.
Where can I find the Introduction to Database Management System book-back answers?
The correct option for each question is highlighted on this page with a worked explanation, plus a quick answer-key summary at the top.
