DATABASE ADMINISTRATOR QUESTIONS AND ANSWERS

 DATABASE ADMINISTRATOR QUESTIONS AND ANSWERS

Section A: Database Fundamentals (1–15)

1. A database is best described as:
   A. A collection of programs
   B. A collection of related data
   C. A programming language
   D. A storage device
   Answer: B
2. DBMS stands for:
   A. Data Backup Management System
   B. Database Management System
   C. Digital Base Management System
   D. Data Binary Management System
   Answer: B
3. Which of the following is NOT a DBMS?
   A. MySQL
   B. Oracle
   C. PostgreSQL
   D. Python
   Answer: D
4. The person responsible for managing databases is called:
   A. Programmer
   B. System Analyst
   C. Database Administrator
   D. Network Engineer
   Answer: C
5. Which level of database architecture describes how data is stored?
   A. External
   B. Conceptual
   C. Internal
   D. Logical
   Answer: C
6. The logical structure of a database is known as:
   A. Schema
   B. Table
   C. Index
   D. Instance
   Answer: A
7. A table row is also known as:
   A. Attribute
   B. Record
   C. Field
   D. Key
   Answer: B
8. A table column is also known as:
   A. Tuple
   B. Record
   C. Attribute
   D. Row
   Answer: C
9. Which key uniquely identifies a record?
   A. Foreign key
   B. Candidate key
   C. Primary key
   D. Composite key
   Answer: C
10. A foreign key is used to:
    A. Uniquely identify records
    B. Improve performance
    C. Link tables
    D. Encrypt data
    Answer: C
11. Which model uses tables to store data?
    A. Hierarchical
    B. Network
    C. Relational
    D. Object-oriented
    Answer: C
12. SQL is used to:
    A. Design networks
    B. Manage databases
    C. Write operating systems
    D. Create hardware
    Answer: B
13. Which command is used to retrieve data?
    A. INSERT
    B. UPDATE
    C. DELETE
    D. SELECT
    Answer: D
14. Which command removes a table permanently?
    A. DELETE
    B. DROP
    C. TRUNCATE
    D. REMOVE
    Answer: B
15. Which normal form removes transitive dependency?
    A. 1NF
    B. 2NF
    C. 3NF
    D. BCNF
    Answer: C

 

Section B: SQL & Query Management (16–35)

16. Which SQL clause filters records?
    A. ORDER BY
    B. GROUP BY
    C. WHERE
    D. HAVING
    Answer: C
17. Which function returns the number of rows?
    A. SUM()
    B. COUNT()
    C. AVG()
    D. MAX()
    Answer: B
18. Which JOIN returns matching records only?
    A. LEFT JOIN
    B. RIGHT JOIN
    C. FULL JOIN
    D. INNER JOIN
    Answer: D
19. Which JOIN returns all records from the left table?
    A. RIGHT JOIN
    B. LEFT JOIN
    C. FULL JOIN
    D. INNER JOIN
    Answer: B
20. Which keyword sorts results?
    A. SORT
    B. ORDER BY
    C. GROUP BY
    D. FILTER
    Answer: B
21. Which command changes table structure?
    A. UPDATE
    B. ALTER
    C. MODIFY
    D. CHANGE
    Answer: B
22. Which constraint prevents NULL values?
    A. UNIQUE
    B. PRIMARY KEY
    C. NOT NULL
    D. CHECK
    Answer: C
23. Which constraint enforces data uniqueness?
    A. CHECK
    B. NOT NULL
    C. UNIQUE
    D. DEFAULT
    Answer: C
24. A view is:
    A. A physical table
    B. A virtual table
    C. An index
    D. A trigger
    Answer: B
25. Which command removes all rows but keeps table structure?
    A. DELETE
    B. DROP
    C. TRUNCATE
    D. REMOVE
    Answer: C
26. Which clause is used with aggregate functions?
    A. WHERE
    B. GROUP BY
    C. ORDER BY
    D. DISTINCT
    Answer: B
27. Which operator checks for a range of values?
    A. LIKE
    B. BETWEEN
    C. IN
    D. EXISTS
    Answer: B
28. Which operator checks pattern matching?
    A. LIKE
    B. IN
    C. BETWEEN
    D. IS
    Answer: A
29. Which SQL command is DDL?
    A. SELECT
    B. INSERT
    C. CREATE
    D. UPDATE
    Answer: C
30. Which SQL command is DML?
    A. DROP
    B. CREATE
    C. INSERT
    D. ALTER
    Answer: C
31. Which SQL command is TCL?
    A. COMMIT
    B. SELECT
    C. INSERT
    D. CREATE
    Answer: A
32. Which SQL command is DCL?
    A. GRANT
    B. SELECT
    C. INSERT
    D. UPDATE
    Answer: A
33. Which index improves query performance?
    A. Clustered
    B. Non-clustered
    C. Primary
    D. All of the above
    Answer: D
34. Which statement removes duplicate rows?
    A. UNIQUE
    B. DISTINCT
    C. GROUP BY
    D. HAVING
    Answer: B
35. Which SQL feature ensures data consistency?
    A. Index
    B. Constraint
    C. Trigger
    D. View
    Answer: B

Section C: DBA Roles, Security & Performance (36–70)

36. Which is a DBA responsibility?
    A. Data entry
    B. Database backup
    C. Writing applications
    D. Network cabling
    Answer: B
37. Backup ensures protection against:
    A. Virus only
    B. Power failure only
    C. Data loss
    D. Slow queries
    Answer: C
38. Which backup copies only changed data?
    A. Full
    B. Differential
    C. Incremental
    D. Mirror
    Answer: C
39. Which backup is fastest to restore?
    A. Incremental
    B. Differential
    C. Full
    D. Partial
    Answer: C
40. Which ensures authorized access?
    A. Indexing
    B. Normalization
    C. Authentication
    D. Replication
    Answer: C
41. Which command gives user permission?
    A. REVOKE
    B. ALLOW
    C. GRANT
    D. ASSIGN
    Answer: C
42. Which command removes permission?
    A. DENY
    B. DELETE
    C. DROP
    D. REVOKE
    Answer: D
43. Encryption protects data:
    A. At rest
    B. In transit
    C. Both
    D. None
    Answer: C
44. Which improves query speed?
    A. Backup
    B. Index
    C. Trigger
    D. View
    Answer: B
45. Which tool monitors database performance?
    A. Profiler
    B. Compiler
    C. Debugger
    D. Editor
    Answer: A
46. Deadlock occurs when:
    A. Server shuts down
    B. Queries run fast
    C. Transactions wait on each other
    D. Backup fails
    Answer: C
47. Which resolves deadlocks?
    A. Commit
    B. Rollback
    C. Index
    D. View
    Answer: B
48. Which isolation level prevents dirty reads?
    A. Read uncommitted
    B. Read committed
    C. Repeatable read
    D. Serializable
    Answer: B
49. Which isolation level is strictest?
    A. Read committed
    B. Repeatable read
    C. Serializable
    D. Snapshot
    Answer: C
50. ACID stands for:
    A. Atomicity, Consistency, Isolation, Durability
    B. Accuracy, Control, Integrity, Data
    C. Access, Control, Index, Data
    D. Atomic, Consistent, Internal, Durable
    Answer: A

 

Section D: Advanced DBA Concepts (71–100)

71. Replication is used for:
    A. Backup only
    B. Data synchronization
    C. Indexing
    D. Security
    Answer: B
72. Sharding improves:
    A. Security
    B. Scalability
    C. Backup
    D. Normalization
    Answer: B
73. Which database is NoSQL?
    A. Oracle
    B. MySQL
    C. MongoDB
    D. SQL Server
    Answer: C
74. Which NoSQL database is document-based?
    A. Redis
    B. Cassandra
    C. MongoDB
    D. Neo4j
    Answer: C
75. Which NoSQL database is graph-based?
    A. MongoDB
    B. Redis
    C. Neo4j
    D. Cassandra
    Answer: C
76. Which command optimizes tables?
    A. ANALYZE
    B. OPTIMIZE
    C. TUNE
    D. FIX
    Answer: B
77. Which log records all changes?
    A. Error log
    B. Binary log
    C. Query log
    D. Access log
    Answer: B
78. Which ensures high availability?
    A. Backup
    B. Replication
    C. Normalization
    D. Indexing
    Answer: B
79. Which detects slow queries?
    A. Profiler
    B. Slow query log
    C. Error log
    D. Trigger
    Answer: B
80. Which storage ensures durability?
    A. RAM
    B. Cache
    C. Disk
    D. Register
    Answer: C
81. Which feature automates actions on events?
    A. View
    B. Trigger
    C. Index
    D. Cursor
    Answer: B
82. Which cursor processes rows one by one?
    A. Static
    B. Dynamic
    C. Implicit
    D. Explicit
    Answer: D
83. Which tool restores data?
    A. Backup
    B. Index
    C. View
    D. Query
    Answer: A
84. Which database supports stored procedures?
    A. MySQL
    B. Oracle
    C. SQL Server
    D. All of the above
    Answer: D
85. Which ensures minimal redundancy?
    A. Indexing
    B. Normalization
    C. Encryption
    D. Replication
    Answer: B
86. Which process checks data accuracy?
    A. Validation
    B. Indexing
    C. Backup
    D. Recovery
    Answer: A
87. Which DBA task involves planning storage?
    A. Capacity planning
    B. Debugging
    C. Coding
    D. Designing UI
    Answer: A
88. Which improves fault tolerance?
    A. Replication
    B. Normalization
    C. Constraints
    D. Indexing
    Answer: A
89. Which ensures consistency after failure?
    A. Backup
    B. Durability
    C. Atomicity
    D. Isolation
    Answer: B
90. Which process restores database after crash?
    A. Recovery
    B. Replication
    C. Normalization
    D. Indexing
    Answer: A
91. Which command saves a transaction permanently?
    A. ROLLBACK
    B. COMMIT
    C. SAVEPOINT
    D. END
    Answer: B
92. Which command undoes changes?
    A. COMMIT
    B. SAVE
    C. ROLLBACK
    D. END
    Answer: C
93. Which allows partial rollback?
    A. COMMIT
    B. SAVEPOINT
    C. END
    D. STOP
    Answer: B
94. Which is NOT a DBA tool?
    A. pgAdmin
    B. SQL*Plus
    C. Photoshop
    D. SSMS
    Answer: C
95. Which handles concurrent access?
    A. Locking
    B. Backup
    C. Replication
    D. Indexing
    Answer: A
96. Which lock allows read-only access?
    A. Exclusive
    B. Shared
    C. Deadlock
    D. Full
    Answer: B
97. Which ensures data integrity across tables?
    A. Primary key
    B. Foreign key
    C. Index
    D. View
    Answer: B
98. Which improves read-heavy workloads?
    A. Indexing
    B. Encryption
    C. Backup
    D. Logging
    Answer: A
99. Which DBA task ensures compliance?
    A. Auditing
    B. Coding
    C. Designing
    D. Formatting
    Answer: A
100. A DBA must prioritize:
     A. Speed only
     B. Cost only
     C. Security, performance, and availability
     D. UI design
     Answer: C