SSC JE - DBMS 1000+ MCQ [Solved] PDF Download

1. The graphical representation of a query is .
A. B-Tree
B. graph
C. Query Tree
D. directed graph
Answer : C

2. 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

3. The ______ key of a relation is the attribute (column) or collection of attributes, which uniquely identify a given tuple.
A. Primary
B. Foreign
C. Candidate
D. Alternate
Answer : A

4. 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

5. Processed data is called _____
A. Raw data
B. Source
C. Information
D. Useful data
Answer : C

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

7. Which of the syntax is correct for insert statement?
i) insert into values
ii) insert into (column list) values
A. i-only
B. ii-only
C. Both of them
D. None of them
Answer : C

8. In SQL the statement select * from R, S is equivalent to
A. Select * from R natural join S.
B. Select * from R cross join S.
C. Select * from R union join S.
D. Select * from R inner join S.
Answer : B

9. 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

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

11. The keyword to eliminate duplicate rows from the query result in SQL is
A. DISTINCT
B. NO DUPLICATE
C. UNIQUE
D. None of the above
Answer : C

12. In 2NF
A. No functional dependencies (FDs) exist.
B. No multivalued dependencies (MVDs) exist.
C. No partial FDs exist.
D. No partial MVDs exist.
Answer : C

13. In E-R Diagram total participation is represented by
A. Double lines
B. Single line
C. Dashed lines
D. Triangle
Answer : A

14. The part of a database management system which ensures that the data remains in a consistent state is
A. authorization and integrity manager
B. buffer manager
C. transaction manager
D. file manager
Answer : C

15. The full form of GUI is _________
A. Government Union Internet
B. Graphical Unit Interface
C. Graphical User Interface
D. Graphical University Interface
Answer : C

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

17. 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

18. 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

19. ____ table store information about database or about the system.
A. SQL
B. System
C. Nested
D. None of these
Answer : B

20. Shadow paging has
A. no redo
B. no undo
C. redo but no undo
D. neither redo nor undo
Answer : A

21. Whenever two independent one-to-many relationships are mixed in the same relation, a __________ arises.
A. Functional dependency
B. Multi-valued dependency
C. Transitive dependency
D. Partial dependency
Answer : B

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. 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

24. 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

25. ______is a preferred method for enforcing data integrity
A. Constraints
B. Triggers
C. Stored procedure
D. Cursors
Answer : A

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

27. 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

28. Which of the following is a reason to model data?
A. Understand each user's perspective of data
B. Understand the data itself irrespective of the physical representation
C. Understand the use of data across application areas
D. All of the above
Answer : D

29. 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

30. Consider the join of relation R with a relation S. If R has m tuples and S has n tuples, then the maximum and minimum size of the join respectively are
A. m+n and 0
B. m+n and |m-n|
C. mn and 0
D. mn and m+n
Answer : C

31. If a transaction T has obtained an exclusive lock on item Q, then T can
A. read Q
B. write Q
C. both read and write Q
D. write Q but not read Q
Answer : C

32. 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

33. An outstanding functionality of SQL is its support for automatic_____ to the target data.
A. programming
B. navigation
C. functioning
D. notification
Answer : B

34. 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

35. For using a specific database …………… command is used.
A. use database
B. database name use
C. Both A & B
D. None of them
Answer : A

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

37. In an ER diagram the ___shape specifies the Attibute and a ____ shape specifies the primary key attribute.
A. Oval; An oval with an underlined attribute
B. Circle; A circle with bolded attribute inside it
C. Diamond; A bolded attribute
D. Square; An attribute within the square
Answer : A

38. 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

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

40. 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

41. DBMS helps achieve
A. Centralized control of data
B. Data independence
C. Both A and B
D. Neither A nor B
Answer : C

42. The language that requires a user to specify the data to be retrieved without specifying exactly how to get it is
A. Procedural DML.
B. Non-Procedural DML.
C. Procedural DDL.
D. Non-Procedural DDL.
Answer : B

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

44. Data items grouped together for storage purposes are called a
A. record
B. string
C. title
D. list
Answer : A

45. 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

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

48. The metadata is created by the
A. DML compiler
B. DML pre-processor
C. DDL interpreter
D. Query interpreter
Answer : C

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

50. The division operator divides a dividend A of degree m+n by a divisor relation B of degree n and produces a result of degree
A. m - 1
B. m + 1
C. m * m
D. m
Answer : D