CSS - PMS - CCE - PCS - Basic Computing
Database Basics
The process of verifying a user's identity is called:
A. Authentication
B. Authorization
C. Normalization
D. Aggregation
Correct Answer: A
Authentication confirms who the user is, commonly through passwords or other credentials.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which command should be used to undo an unsuccessful transaction?
A. ROLLBACK
B. COMMIT
C. GRANT
D. CREATE
Correct Answer: A
ROLLBACK cancels uncommitted changes and restores the previous consistent state.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which command should be used after a transaction has completed successfully?
A. COMMIT
B. ROLLBACK
C. DROP
D. REVOKE
Correct Answer: A
COMMIT permanently records the completed transaction.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A situation in which two transactions wait indefinitely for each other's locked resources is called:
A. Deadlock
B. Backup
C. Normalization
D. Replication
Correct Answer: A
A deadlock occurs when transactions form a circular wait and none can proceed.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A mechanism that restricts other transactions from changing data being used is called a:
A. Lock
B. Form
C. Report
D. Alias
Correct Answer: A
A lock protects data during a transaction and helps prevent conflicting updates.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
The process of controlling simultaneous database access is called:
A. Concurrency control
B. Page formatting
C. Report printing
D. File compression
Correct Answer: A
Concurrency control prevents conflicting simultaneous operations from damaging data consistency.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In ACID properties, Durability means:
A. Committed changes survive system failure
B. All queries are temporary
C. All data is deleted after logout
D. Only backup files are stored
Correct Answer: A
Durability ensures that committed data remains stored even after a crash or restart.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In ACID properties, Isolation means:
A. Concurrent transactions do not improperly interfere with each other
B. The database must be disconnected from a network
C. Every table must be stored separately
D. Only one user can ever use the system
Correct Answer: A
Isolation controls how concurrent transactions see and affect one another.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In ACID properties, Consistency means:
A. A transaction moves the database from one valid state to another
B. Every row must contain the same value
C. Every table must have the same number of columns
D. All users see different rules
Correct Answer: A
Consistency means database rules and constraints remain valid before and after a transaction.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
In ACID properties, Atomicity means:
A. All transaction operations occur or none occur
B. Data is always alphabetically sorted
C. Every user has administrator rights
D. The database is stored only in memory
Correct Answer: A
Atomicity ensures that a transaction is completed entirely or rolled back entirely.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
A sequence of database operations treated as one logical unit is called a:
A. Transaction
B. Report
C. Schema
D. View
Correct Answer: A
A transaction groups operations so they succeed or fail together.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which database feature helps ensure that entered data follows required rules?
A. Constraints
B. Wallpaper
C. Screensaver
D. Printer driver
Correct Answer: A
Constraints enforce rules such as uniqueness, valid ranges, required values, and references.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Why are data types important?
A. They control valid values, storage, and operations
B. They remove the need for tables
C. They automatically create every query
D. They prevent all hardware failures
Correct Answer: A
Data types define what kind of values a field may hold and which operations are valid.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which statement about NULL and zero is correct?
A. They are different
B. They are always identical
C. NULL is always larger
D. Zero cannot be stored
Correct Answer: A
Zero is an actual numeric value, while NULL means no known or applicable value is present.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
What does NULL represent in a database?
A. A missing, unknown, or not applicable value
B. The number zero
C. An empty table only
D. A guaranteed false value
Correct Answer: A
NULL represents the absence of a known value; it is not the same as zero or an empty string.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which data type is suitable for exact monetary values?
A. DECIMAL
B. IMAGE
C. BOOLEAN
D. DATE
Correct Answer: A
DECIMAL or NUMERIC stores exact fixed-precision values and is suitable for money.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which data type commonly stores true or false values?
A. BOOLEAN
B. VARCHAR
C. DATE
D. DECIMAL
Correct Answer: A
BOOLEAN represents logical values such as TRUE and FALSE.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which data type is intended to store calendar dates?
A. DATE
B. INTEGER
C. BOOLEAN
D. CHAR only
Correct Answer: A
DATE stores date values in a format the DBMS can validate, sort, and calculate.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which data type usually stores fixed-length text?
A. CHAR
B. VARCHAR
C. FLOAT
D. DATE
Correct Answer: A
CHAR stores text using a fixed defined length, often padding shorter values.
CSS - PMS - CCE - PCS - Basic Computing
Database Basics
Which data type is normally used for variable-length text?
A. VARCHAR
B. INTEGER
C. DATE
D. BINARY only
Correct Answer: A
VARCHAR stores text with varying length up to a defined maximum.