Q1. Which of the following correctly arranges the data hierarchy from the smallest unit to the largest unit in a computer database?

A) Bit →→ Byte →→ Field →→ Record →→ File →→ Database

B) Bit →→ Byte →→ Record →→ Field →→File →→Database

C) Byte →→ Bit →→ File →→ Record →→ Database →→ Field

D) Field →→ Record →→ Byte →→ Bit →→ Database →→ File

E) Database →→ File →→ Record →→ Field →→ Byte →→ Bit

Answer: A

 

Q2. In a Relational Database Management System (RDBMS), the term "Tuple" is technically synonymous with which component of a table?

A) A Column

B) A Row

C) A Table

D) An Attribute

E) A Key

Answer: B (Row).

 

Q3. Which specific Key is defined as a set of one or more attributes that can uniquely identify a record in a table, but serves as a pool from which the Primary Key is chosen?

A) Foreign Key

B) Secondary Key

C) Candidate Key

D) Alternate Key

E) Super Key

Answer: C (Candidate Keys are the "candidates" for the job of Primary Key).

 

Q4. The SQL command "DROP" removes a table and its structure permanently from the database. Which category of SQL commands does it belong to?

A) DML (Data Manipulation Language)

B) DDL (Data Definition Language)

C) DCL (Data Control Language)

D) TCL (Transaction Control Language)

E) DQL (Data Query Language)

Answer: B (Defines or destroys structure).

 

Q5. What is the primary function of a "Foreign Key" in a relational database table?

A) To ensure that no two rows have the same data in that column.

B) To encrypt the data in the table.

C) To link two tables together by referencing the Primary Key of another table.

D) To allow NULL values in the Primary Key column.

E) To automatically sort the data.

Answer: C

 

Q6. Which property of a database transaction ensures that "All operations within the transaction are completed successfully, or none of them are applied" (The All-or-Nothing rule)?

A) Isolation

B) Durability

C) Consistency

D) Atomicity

E) Redundancy

Answer: D

 

Q7. The situation in a database where the same piece of data is held in two separate places is known as:

A) Data Integrity

B) Data Redundancy

C) Data Inconsistency

D) Data Independence

E) Data Mining

Answer: B (Redundancy = Repetition).

 

Q8. Which specific SQL command is used to retrieve or "fetch" data from a database table based on specific criteria?

A) UPDATE

B) GET

C) OPEN

D) SELECT

E) INSERT

Answer: D

 

Q9. In the context of database normalization, the main goal is to:

A) Increase data redundancy to ensure backups.

B) Minimize data redundancy and dependency to improve integrity.

C) Create as many tables as possible.

D) Combine all data into one giant table.

E) Make the database run slower but safer.

Answer: B

 

Q10. Which of the following is an example of an "Open Source" DBMS software?

A) Oracle Database

B) Microsoft SQL Server

C) MySQL

D) Microsoft Access

E) IBM Db2

Answer: C (MySQL is open source; others are largely proprietary).

 

Q11. A column in a database table that contains a specific detail, such as "Employee Name," is technically referred to as a(n):

A) Tuple

B) Attribute

C) Relation

D) Degree

E) Entity

Answer: B

 

Q12. What does the acronym "SQL" stand for in the context of databases?

A) Structured Question Language

B) Standard Query Logic

C) Simple Query Language

D) Structured Query Language

E) Standard Question Logic

Answer: D

 

Q13. If a Primary Key consists of two or more columns combined together to create a unique value, it is called a:

A) Foreign Key

B) Composite Key

C) Candidate Key

D) Alternate Key

E) Super Key

Answer: B

 

Q14. The "Degree" of a relation (table) in a database refers to the:

A) Number of Rows (Tuples)

B) Number of Columns (Attributes)

C) Number of Tables in the database

D) Size of the database in MB

E) Number of relationships

Answer: B

 

Q15. The "Cardinality" of a relation (table) refers to the:

A) Number of Rows (Tuples)

B) Number of Columns (Attributes)

C) Number of Keys

D) Complexity of the data

E) Speed of the query

Answer: A

 

Q16. Which SQL command allows you to modify the existing records in a table (e.g., changing a student's address)?

A) ALTER

B) MODIFY

C) UPDATE

D) CHANGE

E) EDIT

Answer: C (UPDATE changes data; ALTER changes structure).

 

Q17. Which of the following is NOT a valid constraint in SQL?

A) PRIMARY KEY

B) UNIQUE

C) NOT NULL

D) CHECK

E) BOTTOM

Answer: E

 

Q18. The process of analyzing large datasets to find hidden patterns and relationships is known as:

A) Data Warehousing

B) Data Mining

C) Data Entry

D) Data Logging

E) Normalization

Answer: B

 

Q19. What is the function of the "COMMIT" command in SQL?

A) To delete the table.

B) To permanently save all changes made in the current transaction.

C) To undo the changes made.

D) To grant permission to a user.

E) To lock the database.

Answer: B

 

Q20. An "Entity-Relationship (E-R) Diagram" is a graphical representation used to:

A) Design the logical structure of a database.

B) Write SQL code.

C) Draw charts in Excel.

D) Test the speed of the database.

E) Connect the internet.

Answer: A

 

Q21. In an E-R Diagram, an "Entity" (like a Student or Car) is represented by which shape?

A) Diamond

B) Oval

C) Rectangle

D) Triangle

E) Circle

Answer: C

 

Q22. In an E-R Diagram, an "Attribute" (like Name or Age) is represented by which shape?

A) Rectangle

B) Oval / Ellipse

C) Diamond

D) Square

E) Line

Answer: B

 

Q23. The ability to modify the schema (structure) of a database at one level without affecting the schema at the next higher level is called:

A) Data Independence

B) Data Isolation

C) Data Redundancy

D) Data Security

E) Data Mining

Answer: A

 

Q24. A collection of data designed to support management decision-making (historical data analysis) is called a:

A) Data Mine

B) Data Warehouse

C) Relational Database

D) Operational Database

E) Flat File

Answer: B (Warehouses store historical data for analysis).

 

Q25. Which normal form (Normalization) states that a table must not have any "Partial Dependencies" (meaning non-key attributes must depend on the whole primary key)?

A) First Normal Form (1NF)

B) Second Normal Form (2NF)

C) Third Normal Form (3NF)

D) BCNF

E) 4NF

Answer: B

 

Q26. Which specific SQL command is used to add a new column to an existing table structure?

A) INSERT COLUMN

B) UPDATE TABLE

C) ALTER TABLE

D) ADD FIELD

E) MODIFY TABLE

Answer: C (Uses ALTER TABLE table_name ADD column_name datatype).

 

Q27. The concept of "Referential Integrity" ensures that:

A) Data is encrypted.

B) A Foreign Key value must match an existing Primary Key value in the parent table (no broken links).

C) The database is backed up daily.

D) Users have strong passwords.

E) All tables have the same number of rows.

Answer: B

 

Q28. In a database, NULL values represent:

A) The number Zero.

B) A blank space character.

C) Missing, unknown, or inapplicable data.

D) An error in the system.

E) The maximum value.

Answer: C

 

Q29. Which of the following commands is used to remove all records from a table but keep the table structure intact (and is faster than DELETE)?

A) DROP

B) REMOVE

C) TRUNCATE

D) ERASE

E) CUT

Answer: C

 

Q30. "DBA" stands for:

A) Data Base Access

B) Database Administrator

C) Data Basic Authority

D) Database Authentication

E) Data Backup Agency

Answer: B (The person in charge of the database).

 

Q31. Which view of the database architecture describes "what" data is stored and the relationships among them (the logical view)?

A) Physical Level

B) Conceptual (Logical) Level

C) External (View) Level

D) Hardware Level

E) User Level

Answer: B

 

Q32. In SQL, the "ORDER BY" clause is used to:

A) Filter the data.

B) Sort the result-set in ascending or descending order.

C) Group specific data together.

D) Select specific columns.

E) Join two tables.

Answer: B

 

Q33. A "View" in a database is best described as:

A) A physical table containing data.

B) A virtual table based on the result-set of an SQL statement (it contains no data of its own).

C) A backup of the database.

D) A graph of the data.

E) The screen the user sees.

Answer: B

 

Q34. The "Diamond" shape in an E-R Diagram represents:

A) Entity

B) Attribute

C) Relationship

D) Weak Entity

E) Key

Answer: C

 

Q35. Which of the following is NOT a type of database model?

A) Hierarchical Model

B) Network Model

C) Relational Model

D) Flowchart Model

E) Object-Oriented Model

Answer: D

 

Q36. The constraint that creates a unique index on a column and does not allow duplicate values, but DOES allow one NULL value, is:

A) PRIMARY KEY

B) FOREIGN KEY

C) UNIQUE

D) CHECK

E) DEFAULT

Answer: C (Primary Key allows NO Nulls; Unique allows one).

 

Q37. "Metadata" is essentially defined as:

A) Data about Data.

B) Massive data.

C) Corrupted data.

D) Audio/Video data.

E) Encrypted data.

Answer: A (e.g., The data telling you how long a column is, or what type of data it holds).

 

Q38. Which operator is used in SQL to search for a specified pattern in a column (using wildcards like %)?

A) LIKE

B) SAME

C) MATCH

D) EQUAL

E) AS

Answer: A (e.g., WHERE name LIKE 'A%')

 

Q39. In the ACID properties, "Isolation" implies that:

A) The database is isolated from the internet.

B) Multiple transactions occurring at the same time must not affect each other's execution.

C) Data is stored on an isolated hard drive.

D) Users must work in isolation.

E) One transaction must delete the other.

Answer: B

 

Q40. The SQL command "GRANT" is used to:

A) Create a new table.

B) Give specific privileges/permission to a user.

C) Insert data.

D) Save the transaction.

E) Delete a user.

Answer: B (Part of DCL).

 

Q41. A "Weak Entity" in an E-R Diagram is one that:

A) Has no attributes.

B) Cannot be uniquely identified by its own attributes alone (needs a Foreign Key from a strong entity).

C) Has too many attributes.

D) Is not connected to anything.

E) Contains NULL values.

Answer: B

 

Q42. Which normal form eliminates "Transitive Dependency" (A -> B, B -> C)?

A) 1NF

B) 2NF

C) 3NF

D) 4NF

E) 5NF

Answer: C

 

Q43. The "DISTINCT" keyword in SQL is used to:

A) Select all records.

B) Return only different (unique) values, eliminating duplicates in the output.

C) Sort the data.

D) Delete distinct records.

E) Count the records.

Answer: B

 

Q44. Which type of failure occurs when the database system crashes due to a power loss or OS failure, but the disk storage is not damaged?

A) Disk Failure

B) Transaction Failure

C) System Crash (Soft Crash)

D) Media Failure

E) Application Error

Answer: C

 

Q45. The language used by application programs to request data from the DBMS is referred to as:

A) DML

B) DDL

C) Query Language

D) Host Language

E) Assembly Language

Answer: C (specifically DML embedded in a query).

 

Q46. "Data Integrity" refers to:

A) The speed of data access.

B) The size of the database.

C) The accuracy and consistency of data stored in the database.

D) The security of the database password.

E) The ability to backup data.

Answer: C

 

Q47. Which SQL aggregate function returns the total number of rows that match a specified criterion?

A) SUM()

B) AVG()

C) TOTAL()

D) COUNT()

E) MAX()

Answer: D

 

Q48. In a "One-to-Many" relationship (e.g., One Teacher, Many Students), the Foreign Key is placed in:

A) The "One" side table (Teacher).

B) The "Many" side table (Student).

C) Both tables.

D) A third separate table.

E) Neither table.

Answer: B (The Student table holds the Teacher_ID to link back).

 

Q49. "Warehousing" data involves usually data that is:

A) Read-Only and Historical.

B) Frequently updated.

C) Unorganized.

D) Temporary.

E) Volatile.

Answer: A

 

Q50. The command "ROLLBACK" is used to:

A) Delete the database.

B) Restore the database to the last committed state (undo un-saved changes).

C) Move the database to a tape drive.

D) Scroll down the table.

E) Restart the computer.

Answer: B

 

Q51. Which level of data abstraction describes exactly how the data is actually stored on the storage medium (HDD/SSD) using complex data structures?

A) Physical Level

B) Logical Level

C) View Level

D) Conceptual Level

E) External Level

Answer: A (The lowest level).

 

Q52. In SQL, which wildcard character represents a single character?

A) % (Percentage)

B) * (Asterisk)

C) _ (Underscore)

D) ? (Question Mark)

E) # (Hash)

Answer: C (Note: In MS Access it is '?', but in standard SQL it is '_').

 

Q53. A "Trigger" in a database is:

A) A button to delete data.

B) A stored procedure that automatically executes (fires) in response to certain events (like Insert/Update) on a table.

C) A type of virus.

D) A backup command.

E) A manual switch.

Answer: B

 

Q54. Which of the following is NOT a valid Aggregate Function in standard SQL?

A) MIN()

B) MAX()

C) AVG()

D) COUNT()

E) LENGTH()

Answer: E (LENGTH is a Scalar function, not Aggregate).

 

Q55. The specific SQL clause "GROUP BY" is usually used in conjunction with:

A) INSERT statements.

B) Aggregate functions (like SUM, COUNT) to group the result-set by one or more columns.

C) DELETE statements.

D) CREATE TABLE statements.

E) GRANT commands.

Answer: B

 

Q56. What is the technical term for a key that consists of two or more attributes that uniquely identify an entity occurrence?

A) Foreign Key

B) Secondary Key

C) Compound (Composite) Key

D) Simple Key

E) Domain Key

Answer: C

 

Q57. In the relational model, the number of attributes (columns) in a relation is called its:

A) Cardinality

B) Degree

C) Domain

D) Tuple

E) Size

Answer: B

 

Q58. Which operation is used to combine rows from two or more tables, based on a related column between them?

A) JOIN

B) MERGE

C) COMBINE

D) LINK

E) CONNECT

Answer: A

 

Q59. The "INNER JOIN" keyword selects records that have matching values in:

A) The Left table only.

B) The Right table only.

C) Both tables.

D) Neither table.

E) The first 10 rows.

Answer: C

 

Q60. A "Stored Procedure" is:

A) A physically stored table.

B) A prepared SQL code that you can save, so the code can be reused over and over again.

C) A backup of the database.

D) A log of errors.

E) A type of user permission.

Answer: B

 

Q61. Which normal form deals with "Multivalued Dependencies"?

A) 2NF

B) 3NF

C) BCNF

D) 4NF

E) 5NF

Answer: D

 

Q62. "Data Mining" is often used to:

A) Encrypt data.

B) Discover patterns, correlations, and anomalies in large datasets (Knowledge Discovery).

C) Delete old data.

D) Create new tables.

E) Reset passwords.

Answer: B

 

Q63. The full form of ODBC is:

A) Open Data Base Connectivity

B) Open Data Base Control

C) Oracle Data Base Connect

D) Object Data Base Connectivity

E) Open Data Basic Code

Answer: A (A standard API for accessing DBMS).

 

Q64. In an E-R Diagram, a "Double Rectangle" represents:

A) Strong Entity

B) Weak Entity

C) Relationship

D) Attribute

E) Multi-valued Attribute

Answer: B

 

Q65. Which SQL command is used to remove a specific privilege (permission) from a user?

A) DELETE

B) DENY

C) REVOKE

D) REMOVE

E) WITHDRAW

Answer: C

 

Q66. The "HAVING" clause in SQL is used to filter data:

A) Before grouping.

B) After grouping (used with Aggregate functions).

C) During insertion.

D) Without grouping.

E) In the SELECT part.

Answer: B (WHERE filters rows; HAVING filters groups).

 

Q67. "Big Data" is characterized by the 3 Vs. What are they?

A) Value, Vacuum, Velocity

B) Volume, Velocity, Variety

C) Volume, Vision, Voice

D) Velocity, Verification, Validity

E) Variety, Value, Video

Answer: B

 

Q68. Which type of database stores data in objects rather than tables?

A) Relational Database (RDBMS)

B) Object-Oriented Database (OODBMS)

C) Network Database

D) Hierarchical Database

E) Flat File

Answer: B

 

Q69. The command "SAVEPOINT" is used in SQL transactions to:

A) Save the file to the hard disk.

B) Temporarily save a transaction so you can rollback to that point if needed.

C) Stop the database.

D) Print the data.

E) Save the password.

Answer: B

 

Q70. Which of the following is a DQL (Data Query Language) command?

A) INSERT

B) UPDATE

C) SELECT

D) DELETE

E) CREATE

Answer: C

 

Q71. In a database, "Atomicity" guarantees that:

A) Atoms are split.

B) Transactions are treated as a single unit (All or Nothing).

C) Data is atomic (small).

D) Users are atomic.

E) Hardware is atomic.

Answer: B

 

Q72. A "Deadlock" in a DBMS occurs when:

A) The power goes out.

B) Two transactions wait indefinitely for each other to release a lock.

C) The hard drive is full.

D) A user forgets their password.

E) The internet is slow.

Answer: B

 

Q73. Which of the following keys allows NULL values?

A) Primary Key

B) Foreign Key (unless specified NOT NULL)

C) Candidate Key (depends on implementation, but theoretically unique)

D) Super Key

E) None of the above

Answer: B (FKs can be Null, meaning no relationship exists for that row).

 

Q74. The "BETWEEN" operator in SQL selects values:

A) Within a given range.

B) Outside a range.

C) Exactly equal to two values.

D) That are null.

E) That are text only.

Answer: A

 

Q75. Which SQL constraint ensures that all values in a column are different?

A) NOT NULL

B) UNIQUE

C) CHECK

D) DEFAULT

E) INDEX

Answer: B

 

Q76. The "CHECK" constraint is used to:

A) Check for spelling errors.

B) Limit the value range that can be placed in a column (e.g., Age > 18).

C) Verify the password.

D) Check if the table exists.

E) Check for duplicate keys.

Answer: B

 

Q77. What is "Normalization"?

A) Mixing all data together.

B) The process of organizing data to minimize redundancy and dependency.

C) Making the database larger.

D) Deleting tables.

E) Converting text to numbers.

Answer: B

 

Q78. In 1NF (First Normal Form), a table must:

A) Have no transitive dependencies.

B) Have atomic (indivisible) values in each column (no list of items in one cell).

C) Have a composite key.

D) Be linked to another table.

E) Be empty.

Answer: B

 

Q79. Which join returns all records from the Left table, and the matched records from the Right table?

A) Inner Join

B) Right Join

C) Left Join

D) Full Join

E) Cross Join

Answer: C

 

Q80. The "Cartesian Product" (CROSS JOIN) of two tables with 4 rows and 5 rows respectively will result in how many rows?

A) 9

B) 4

C) 5

D) 20

E) 0

Answer: D (4 x 5 = 20).

 

Q81. "Data Dictionary" is:

A) A book about data.

B) A centralized repository of information about data such as meaning, relationships, origin, usage, and format.

C) A list of passwords.

D) A backup file.

E) An English dictionary.

Answer: B

 

Q82. The term "Schema" refers to:

A) The actual data in the database.

B) The logical structure or blueprint of the database.

C) The physical hard drive.

D) The software interface.

E) The user manual.

Answer: B

 

Q83. Which of the following is NOT a benefit of using a DBMS?

A) Controlled Redundancy

B) Data Integrity

C) Data Security

D) Increased Complexity and Cost

E) Data Sharing

Answer: D (This is a disadvantage).

 

Q84. "NoSQL" databases are primarily designed for:

A) Small amounts of structured data.

B) Large volumes of unstructured or semi-structured data (Big Data).

C) Banking transactions strictly.

D) Replacing RAM.

E) Single-user systems.

Answer: B (e.g., MongoDB).

 

Q85. Which SQL function returns the current system date?

A) GETDATE() or SYSDATE (depending on system)

B) TODAYS()

C) NOWDATE()

D) SYSTEM()

E) DATE()

Answer: A

 

Q86. "Concurrency Control" is needed to:

A) Stop users from logging in.

B) Handle multiple transactions executing at the same time to prevent data inconsistency.

C) Speed up the CPU.

D) Save hard drive space.

E) Monitor internet speed.

Answer: B

 

Q87. A "Surrogate Key" is:

A) A natural key like Social Security Number.

B) An artificial key (usually just an incrementing number) generated by the database to uniquely identify a row.

C) A foreign key.

D) A password.

E) A duplicate key.

Answer: B

 

Q88. Which operator allows you to specify multiple values in a WHERE clause?

A) LIKE

B) BETWEEN

C) IN

D) AND

E) OR

Answer: C (e.g., WHERE color IN ('Red', 'Blue', 'Green')).

 

Q89. The "AS" keyword in SQL is used to:

A) Rename a column or table with an alias (temporary name).

B) Join tables.

C) Filter data.

D) Delete data.

E) Create a user.

Answer: A

 

Q90. Which of the following is considered "Unstructured Data"?

A) An Excel spreadsheet.

B) A SQL Table.

C) Emails, Videos, and Social Media posts.

D) A CSV file.

E) A phone book.

Answer: C

 

Q91. "Data Independence" comes in two types:

A) Physical and Logical.

B) Hardware and Software.

C) Internal and External.

D) Primary and Secondary.

E) Strong and Weak.

Answer: A

 

Q92. The "Diamond" in an E-R diagram represents a relationship. If it has a double line, it signifies:

A) Partial Participation.

B) Total Participation (Every entity must be involved).

C) Weak Relationship.

D) Error.

E) Optional Relationship.

Answer: B

 

Q93. "Denormalization" is the process of:

A) Adding redundancy back into the database to improve read performance (speed).

B) Fixing errors.

C) Deleting tables.

D) Encrypting data.

E) Compressing files.

Answer: A

 

Q94. Which command is used to permanently save the work in a transaction?

A) ROLLBACK

B) COMMIT

C) SAVEPOINT

D) GRANT

E) TRUNCATE

Answer: B

 

Q95. The "Full Form" of RDBMS is:

A) Real Database Management System

B) Relational Database Management System

C) Rotating Database Management System

D) Rapid Database Management System

E) Reliable Database Management System

Answer: B

 

Q96. Which constraint prevents invalid data from being entered into the foreign key column?

A) Unique Constraint

B) Referential Integrity Constraint

C) Null Constraint

D) Check Constraint

E) Index Constraint

Answer: B

 

Q97. An "Index" in a database is used to:

A) Hide data.

B) Speed up data retrieval (searching).

C) Secure data.

D) Delete data.

E) Store data.

Answer: B

 

Q98. "OLAP" stands for:

A) Online Analytical Processing

B) Online Advanced Processing

C) Offline Analytical Processing

D) Online Automated Processing

E) Online Access Protocol

Answer: A

 

Q99. "OLTP" stands for:

A) Online Transaction Processing

B) Online Table Processing

C) Offline Transaction Protocol

D) Online Transfer Protocol

E) Old Transaction Processing

Answer: A

 

Q100. In SQL, comments are added using:

A) // (Double Slash)

B) -- (Double Dash)

C) # (Hash)

D) /* ... */

E) Both B and D are common standards.

Answer: E