1000+ DBMS Multiple Choice Question Answer [Solved]

1. The clause alter table in SQL can be used to
A. add an attribute
B. delete an attribute
C. alter the default values of an attribute
D. all of the above
Answer : D

2. Tree structures are used to store data in
A. Network model.
B. Relational model.
C. Hierarchical model.
D. File based system.
Answer : C

3. The _______ is a set of programs to use and / or modify this data.
A. DBMS
B. System
C. Program
D. Software
Answer : A

4. A ____ key specifies a uniqueness constraint that no two distinct tuples in any state r of relation R can have the same value for super key.
A. Sub
B. Parent
C. Candidate
D. Super
Answer : D

5. In a relational schema, each tuple is divided into fields called
A. Relations
B. Queries
C. Domains
D. All of the above
Answer : A

6. A ______ module is typically designed so that it will run on a user workstation or personal computer.
A. Software
B. Server
C. Program
D. Client
Answer : D

7. HSAM stands for ……….
A. Hierarchic Standard Access Method
B. Hierarchic Sequential Access Method
C. Hierarchic Sequential and Method
D. Hierarchic Standard and Method
Answer : B

8. Union operator is a :
A. Unary Operator
B. Ternary Operator
C. Binary Operator
D. Not an operator
Answer : C

9. The concept of mapping of ______ entity types is the concept in which the for each strong entity type E in the ER schema, create a relation R that includes all the simple attributes of E.
A. Regular
B. Irregular
C. None
D. Weak
Answer : A

10. A top-to-bottom relationship among the items in a database is established by a
A. Hierarchical schema
B. Network schema
C. Relational Schema
D. All of the above
Answer : A

11. By ______ an area on disk in certain ways, one can make it represent a bit value of either zero (0) or one (1).
A. Vulcanizing
B. Galvanizing
C. Magnetizing
D. Passing UV rays
Answer : C

12. The statement that is executed automatically by the system as a side effect of the modification of the database is
A. backup
B. assertion
C. recovery
D. trigger
Answer : D

13. Employees in a company are each assigned their own office, i.e. for each employee there exists a unique office and for each office there exists a unique employee; This statement is an example of ____ type of relation.
A. 1:1
B. 1: Many
C. Many: One
D. Many : Many
Answer : A

14. Use of UNIQUE while defining an attribute of a table in SQL means that the attribute values are
A. distinct values
B. cannot have NULL
C. both (A) & (B)
D. same as primary key
Answer : C

15. For correct behaviour during recovery, undo and redo operation must be
A. Commutative
B. Associative
C. idempotent
D. distributive
Answer : C

16. The size of a data item is called its _______, which can be a field of some record or may be a larger unit such as a record.
A. Similarity
B. Granularity
C. Dimensionality
D. Arity
Answer : B

17. In b-tree the number of keys in each node is than the number of its children.
A. one less
B. same
C. one more
D. half
Answer : A

18. If an entity can belong to only one lower level entity then the constraint is
A. disjoint
B. partial
C. overlapping
D. single
Answer : B

19. An advantage of views is
A. Data security
B. Derived columns
C. Hiding of complex queries
D. All of the above
Answer : A

20. Cascading rollback is avoided in all protocol except
A. strict two-phase locking protocol.
B. tree locking protocol
C. two-phase locking protocol
D. validation based protocol.
Answer : D

21. Which of the following relational algebra operations do not require the participating tables to be union-compatible?
A. Union
B. Intersection
C. Difference
D. Join
Answer : D

22. Which of the following is not a consequence of concurrent operations?
A. Lost update problem.
B. Update anomaly.
C. Unrepeatable read.
D. Dirty read.
Answer : B

23. In SQL, testing whether a subquery is empty is done using
A. DISTINCT
B. UNIQUE
C. NULL
D. EXISTS
Answer : D

24. What is data integrity?
A. It is the data contained in database that is non redundant.
B. It is the data contained in database that is accurate and consistent.
C. It is the data contained in database that is secured.
D. It is the data contained in database that is shared.
Answer : B

25. Which normal form is considered adequate for normal relational database design?
A. 2NF
B. 5NF
C. 4NF
D. 3NF
Answer : D

26. The data models defined by ANSI/SPARC architecture are
A. Conceptual, physical and internal
B. Conceptual, view and external
C. Logical, physical and internal
D. Logical, physical and view
Answer : D

27. Change Staff table by removing default of Assistant for position column
A. ALTER TABLE Staff ALTER position DROP DEFAULT;
B. ALTER TABLE Staff ALTER position DEFAULT;
C. ALTER TABLE Staff ALTER DROP DEFAULT;
D. MODIFY Staff ALTER position DROP DEFAULT;
Answer : A

28. An advantage of the database management approach is
A. data redundancy increases
B. data is dependent on programs
C. data is integrated and can be accessed by multiple programs
D. none of the above
Answer : C

29. Between DRAM and magnetic disk storage another form of memory, called ______ memory is becoming common because it is non volatile.
A. RAM
B. Flash
C. Hard Disk
D. Secondary
Answer : B

30. Relations produced from an E-R model will always be
A. First normal form.
B. Second normal form.
C. Third normal form.
D. Fourth normal form.
Answer : A

31. Precedence graphs help to find a
A. Serializable schedule.
B. Recoverable schedule.
C. Deadlock free schedule.
D. Cascadeless schedule.
Answer : A

32. Drop Table cannot be used to drop a table referenced by a ______ constraint.
A. Primary Key
B. Local Key
C. Foreign Key
D. Composite Key
Answer : C

33. The fact that all employees of a particular organization should not have salaries more than $10000 is a _____ constraint.
A. Schema
B. Tuple
C. Domain
D. Relational
Answer : C

34. Assume transaction A holds a shared lock R. If transaction B also requests for a shared lock on R.
A. It will result in a deadlock situation.
B. It will immediately be rejected.
C. It will immediately be granted.
D. It will be granted as soon as it is released by A .
Answer : C

35. A transaction is in state after the final statement has been executed.
A. partially committed
B. active
C. committed
D. none of the above
Answer : C

36. DBMS is a collection of _____ that enables user to create and maintain a database.
A. Keys
B. Program
C. Translators
D. Language Activity
Answer : B

37. When an E-R diagram is mapped to tables, the representation is redundant for
A. weak entity sets
B. weak relationship sets
C. strong entity sets
D. strong relationship sets
Answer : B

38. If both the functional dependencies : X�Y and Y�X hold for two attributes X and Y then the relationship between X and Y is
A. M:N
B. M:1
C.
D. 1:M
Answer : C

39. Which of the following is not a characteristic of a relational database model?
A. Table
B. Tree like structure
C. Complex logical relationship
D. Records
Answer : B

40. Relational Algebra does not have
A. Selection operator.
B. Projection operator.
C. Aggregation operators.
D. Division operator.
Answer : C

41. A relational database developer refers to a record as
A. an attribute
B. a tuple
C. a criteria
D. a relation
Answer : B

42. Which of the following aggregate functions does not ignore nulls in its results?.
A. COUNT .
B. COUNT (*)
C. MAX
D. MIN
Answer : B

43. Key to represent relationship between tables is called
A. primary key
B. secondary key
C. foreign key
D. none of the above
Answer : C

44. A _____ is used to define overall design of the database
A. code
B. data definition language
C. application program
D. schema
Answer : D

45. _____clause is an additional filter that is applied to the result.
A. Select
B. Order by
C. Group-by
D. Having
Answer : D

46. The default level of consistency in SQL is
A. repeatable read
B. read committed
C. read uncommitted
D. serializable
Answer : D

47. The clause in SQL that specifes that the query result should be sorted in ascending or descending order based on the values of one or more columns is
A. View
B. Order by
C. Group by
D. Having
Answer : B

48. Wait-for graph is used for
A. detecting view serializability.
B. detecting conflict serializability.
C. deadlock prevention
D. deadlock detection
Answer : D

49. The normal form that is not necessarily dependency preserving is
A. 2NF
B. 3NF
C. BCNF
D. 4NF
Answer : A

50. The normalization was first proposed by .
A. Code
B. Codd
C. Boyce Codd
D. Boyce
Answer : B