DBMS MCQ Solved Paper for SSC Scientific Assistant

1. The clause in SQL that specifies 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

2. The transactions like adding an employee, enrolling a student in a course are examples of _______
A. Logical
B. Physical
C. None
D. Theoretical
Answer : A

3. What is a disjoint less constraint?
A. It requires that an entity belongs to no more than one level entity set.
B. The same entity may belong to more than one level.
C. The database must contain an unmatched foreign key value.
D. An entity can be joined with another entity in the same level entity set.
Answer : A

4. The set of all values that can be taken by the attribute is called as _______ of the attribute.
A. Tuple
B. Cardinality
C. Degree
D. Domain
Answer : D

5. The cost of reading and writing temporary files while evaluating a query can be reduced by
A. building indices
B. pipelining
C. join ordering
D. none of the above
Answer : B

6. Which two files are used during operation of the DBMS?
A. Query languages and utilities
B. DML and query language
C. Data dictionary and transaction log
D. Data dictionary and query language
Answer : C

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

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

9. _____is a full form of SQL.
A. Standard query language
B. Sequential query language
C. Structured query language
D. Server side query language
Answer : C

10. According to the levels of abstraction, the schema at the intermediate level is called
A. Logical schema.
B. Physical schema.
C. Subschema.
D. None of the above.
Answer : D

11. 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

12. Which of the following is not a property of transactions?
A. Atomicity
B. Concurrency
C. Isolation
D. Durability
Answer : B

13. operator is used to compare a value to a list of literals values that have been specified.
A. Like
B. COMPARE
C. BETWEEN
D. IN
Answer : A

14. 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

15. Which of the following ensures the atomicity of the transaction?
A. Transaction management component of DBMS
B. Application Programmer
C. Concurrency control component of DBMS
D. Recovery management component of DBMS
Answer : A

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

17. In a multi-user database, if two users wish to update the same record at the same time, they are prevented from doing so by
A. jamming
B. password
C. documentation
D. record lock
Answer : D

18. Dependency preservation is not guaranteed in
A. BCNF
B. 3NF
C. PJNF
D. DKNF
Answer : A

19. In multiple granularity of locks SIX lock is compatible with
A. IX
B. IS
C. S
D. SIX
Answer : B

20. If the closure of an attribute set is the entire relation then the attribute set is a
A. superkey
B. candidate key
C. primary key
D. not a key
Answer : A

21. Which of the following is not a recovery technique?
A. Deferred update
B. Immediate update
C. Two-phase commit
D. Shadow paging
Answer : C

22. 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

23. 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

24. ______defines the structure of a relation which consists of a fixed set of attribute-domain pairs.
A. Instance
B. Program
C. Schema
D. Super Key
Answer : C

25. As per equivalence rules for query transformation, selection operation distributes over
A. Union.
B. Set difference.
C. Intersection.
D. All of the above.
Answer : D

26. Protection of data from unauthorized Disclosure results in loss of _______
A. Integrity
B. Availability
C. Confidentiality
D. Discretionary Security
Answer : C

27. Which of the following is not comparison operator?
A. <>
B. <
C. =<
D. >=
Answer : C

28. The values of the attribute describes a particular
A. Entity set
B. File
C. Entity instance
D. Organization
Answer : C

29. 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

30. Immediate database modification technique uses
A. Both undo and redo.
B. Undo but no redo.
C. Redo but no undo.
D. Neither undo nor redo.
Answer : A

31. Grant and revoke are _____ statements.
A. TCL
B. DCL
C. DDL
D. DML
Answer : B

32. The collection of information stored in a database at a particular moment is called as ......
A. schema
B. instance of the database
C. data domain
D. independence
Answer : B

33. ____specifies a search condition for a group or an aggregate.
A. GROUP BY Clause
B. HAVING Clause
C. FROM Clause
D. WHERE Clause
Answer : B

34. It is an abstraction through which relationships are treated as higher level entities
A. Generalization.
B. Specialization.
C. Aggregation.
D. Inheritance.
Answer : C

35. In an E-R, Y is the dominant entity and X is a subordinate entity. Then which of the following is incorrect :
A. Operationally, if Y is deleted, so is X
B. existence is dependent on Y.
C. Operationally, if X is deleted, so is Y.
D. Operationally, if X is deleted, & remains the same.
Answer : C

36. Which one is correct statement?
Logical data independence provides following without changing application programs:
(i) Changes in access methods.
(ii) Adding new entities in database
(iii) Splitting an existing record into two or more records
(iv) C
A. (i) and (ii)
B. (iv) only
C. (i) and (iv)
D. (ii) and (iii)
Answer : D

37. The data in the database at a particular moment of time is called the _______
A. Snapshot
B. Dynaset
C. Stateless
D. Stateful
Answer : A

38. What will be the number of columns and rows respectively obtained for the operation, A- B, if A B are Base union compatible and all the rows of a are common to B? Assume A has 4 columns and 10 rows; and B has 4 columns and 15 rows
A. 4,0
B. 0,0
C. 4,5
D. 8,5
Answer : A

39. The relational model is based on the concept that data is organized and stored in two-dimensional tables called ______
A. Fields
B. Records
C. Relations
D. Keys
Answer : C

40. 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

41. 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

42. Which of the following concurrency control schemes is not based on the serializability property?
A. Two - phase locking
B. Graph-based locking
C. Time-stamp based locking
D. None of these .
Answer : D

43. 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

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

45. What are the desirable properties of a decomposition
A. Partition constraint.
B. Dependency preservation.
C. Redundancy.
D. Security.
Answer : B

46. 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

47. Isolation of the transactions is ensured by
A. Transaction management
B. Application programmer
C. Concurrency control
D. Recovery management
Answer : C

48. 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

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

50. The ______ language consists of SQL statements for operating on the data (insert, Modify, Delete) in tables that already exist.
A. Data Manipulation
B. Data Definition
C. Data Control
D. None
Answer : A