Unit 3 - Practice Quiz

CSE357 50 Questions
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1 What is the primary function of a Database Management System (DBMS)?

A. To replace the operating system of a computer
B. To manage the storage, retrieval, and modification of data
C. To hide data from users to ensure security
D. To exclusively process mathematical calculations

2 In the context of the Relational Model, what is a relation equivalent to?

A. A Row
B. A Key
C. A Column
D. A Table

3 Which of the following refers to a single row in a relational table?

A. Domain
B. Attribute
C. Schema
D. Tuple

4 What does the term Attribute represent in a database table?

A. A specific column defining a property of the entity
B. A row of data
C. The total number of records
D. The connection between two tables

5 Which SQL command is used to retrieve data from a database?

A. FETCH
B. OPEN
C. GET
D. SELECT

6 Which of the following is considered a Data Definition Language (DDL) command?

A. SELECT
B. INSERT
C. UPDATE
D. CREATE

7 In a relational table, what does the cardinality refer to?

A. The number of rows (tuples)
B. The number of columns
C. The number of keys
D. The distinct values in a column

8 What is a Primary Key?

A. A key that accepts null values
B. A key used only for sorting
C. Any column with numeric data
D. A minimal set of attributes that uniquely identifies a tuple

9 Which concept allows a relation to reference another relation, establishing a link between them?

A. Super Key
B. Alternate Key
C. Primary Key
D. Foreign Key

10 If a table contains the data: , which integrity constraint is violated if column 1 is the Primary Key?

A. Key Integrity
B. Entity Integrity
C. Referential Integrity
D. Domain Integrity

11 Which of the following commands is used to modify existing records in a table?

A. UPDATE
B. CHANGE
C. ALTER
D. MODIFY

12 What is the result of a DELETE command without a WHERE clause?

A. It deletes the first row only
B. It deletes all rows in the table
C. It deletes the table structure
D. It throws a syntax error

13 The set of all possible values that an attribute can take is called its:

A. Range
B. Set
C. Tuple
D. Domain

14 Which of the following keys can act as a Primary Key?

A. Partial Key
B. Secondary Key
C. Foreign Key
D. Candidate Key

15 What is a Super Key?

A. A key that is always an integer
B. A key containing only one attribute
C. A key defined in multiple tables
D. A set of one or more attributes that uniquely identifies a tuple

16 Which SQL clause is used to filter records?

A. WHERE
B. FROM
C. GROUP BY
D. ORDER BY

17 What is Normalization in DBMS?

A. The process of creating backup copies of data
B. The process of encrypting data
C. The process of increasing data duplication for faster access
D. The process of organizing data to reduce redundancy and improve data integrity

18 First Normal Form (1NF) requires that:

A. All attributes contain atomic values
B. There are no transitive dependencies
C. Every determinant is a candidate key
D. There are no partial dependencies

19 Given a relation with Primary Key , if depends on (), and depends on (), which normal form is violated?

A. BCNF
B. 3NF
C. 2NF
D. 1NF

20 Second Normal Form (2NF) is relevant only when:

A. The table has a composite primary key
B. The table has no primary key
C. The table is in 3NF
D. The table has a single-attribute primary key

21 A table is in BCNF (Boyce-Codd Normal Form) if:

A. It is in 1NF
B. For every non-trivial functional dependency , is a super key
C. There are no foreign keys
D. It contains no null values

22 Which of the following is an example of an Update Anomaly?

A. Updating a value in one record leaves inconsistent data in duplicates
B. Deleting a record unintentionally removes other data
C. Unable to insert data because a primary key is missing
D. Data is encrypted and cannot be read

23 What is a Transaction in DBMS?

A. A type of database key
B. The connection between the client and server
C. A logical unit of work that must be processed reliably
D. A single SQL command

24 Which property ensures that a transaction is an 'all-or-nothing' operation?

A. Atomicity
B. Durability
C. Consistency
D. Isolation

25 The Consistency property in ACID ensures that:

A. System failures do not lose data
B. Deadlocks never occur
C. Transactions are executed in isolation
D. The database moves from one valid state to another valid state

26 What does Isolation imply in transaction management?

A. Transactions are atomic
B. Transactions occurring concurrently do not interfere with each other
C. Transactions are saved permanently
D. Transactions are processed sequentially only

27 The Durability property ensures that:

A. Transactions are fast
B. Data is never deleted
C. Once a transaction commits, its changes survive system failures
D. Users cannot access the database during maintenance

28 Which SQL command saves the changes made by a transaction permanently?

A. ROLLBACK
B. SAVEPOINT
C. GRANT
D. COMMIT

29 Which SQL command reverts the database to the state before the transaction began?

A. ROLLBACK
B. UNDO
C. RETURN
D. BACKUP

30 Which state does a transaction enter after the final statement has been executed but before the commit?

A. Active
B. Failed
C. Partially Committed
D. Aborted

31 What is a Deadlock in DBMS?

A. A situation where two or more transactions are waiting for each other to release locks
B. When a transaction fails due to a syntax error
C. A situation where two or more transactions act effectively as a single unit
D. When the database runs out of storage

32 In the context of database keys, what is a Composite Key?

A. A key containing letters and numbers
B. A foreign key that is also a primary key
C. A key that references multiple tables
D. A key composed of two or more attributes

33 What is the degree of a relation with schema ?

A. Variable
B. 4
C. 3
D. Infinite

34 Which of the following creates a Virtual Table based on the result-set of an SQL statement?

A. TABLE
B. INDEX
C. VIEW
D. TRIGGER

35 Which operator is used to search for a specified pattern in a column?

A. LIKE
B. EXISTS
C. BETWEEN
D. IN

36 In functional dependency notation , what is called?

A. Tuple
B. Dependent
C. Determinant
D. Relation

37 Data Independence in DBMS refers to:

A. Independence of data from the database administrator
B. The ability to modify the schema at one level without affecting the schema at the next higher level
C. The ability of data to correct itself
D. The data being stored on a separate server

38 Which aggregate function returns the total number of rows that match a specified criterion?

A. SUM()
B. AVG()
C. COUNT()
D. MAX()

39 Which of the following indicates a Transitive Dependency?

A. and (where is not a candidate key)
B. where is the Primary Key
C.
D.

40 The Two-Phase Locking (2PL) protocol is used for:

A. Normalizing tables
B. Authenticating users
C. Creating backups
D. Concurrency Control

41 Which SQL constraint ensures that all values in a column are different?

A. CHECK
B. UNIQUE
C. DEFAULT
D. NOT NULL

42 In SQL, what is the default sorting order of the ORDER BY clause?

A. Random
B. Ascending (ASC)
C. Descending (DESC)
D. Input Order

43 What is a Foreign Key constraint violation?

A. Leaving a primary key field null
B. Inserting a value in a foreign key column that does not match a primary key in the referenced table
C. Creating a table with the same name as an existing table
D. Inserting a row with a primary key that already exists

44 Which of the following is NOT a type of database key?

A. Candidate Key
B. Major Key
C. Primary Key
D. Alternate Key

45 Lossless Join Decomposition ensures that:

A. The tables cannot be joined
B. Redundancy is increased
C. The join operation is faster
D. No data is lost when tables are joined back together

46 In the context of DBMS, what is an Instance?

A. The collection of information stored in the database at a particular moment
B. The overall design of the database
C. The software used to run the database
D. The data type of a column

47 Which SQL keyword is used to remove duplicate rows from a result set?

A. DISTINCT
B. SEPARATE
C. UNIQUE
D. DIFFERENT

48 What is the purpose of the GROUP BY statement in SQL?

A. To group rows that have the same values in specified columns
B. To sort the result set
C. To join two tables
D. To filter rows based on a condition

49 Which concurrency problem occurs when a transaction reads a value that is being updated by another uncommitted transaction?

A. Phantom Read
B. Lost Update
C. Dirty Read
D. Unrepeatable Read

50 What is the relation between Candidate Keys and Primary Keys?

A. They are always identical
B. Candidate Keys are a subset of Primary Keys
C. They are mutually exclusive
D. Primary Keys are a subset of Candidate Keys