1000+ DBMS MCQ for XAT [Solved]

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

2. 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

3. 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

4. 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

5. Which of the following constitutes a basic set of operations for manipulating relational data?
A. Predicate calculus
B. Relational calculus
C. Relational algebra
D. SQL
Answer : C

6. 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

7. In SQL the word natural can be used with
A. inner join
B. full outer join
C. right outer join
D. all of the above
Answer : A

8. 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

9. 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

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

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

12. ____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

13. If two relations R and S are joined, then the non matching tuples of both R and S are ignored in
A. left outer join
B. right outer join
C. full outer join
D. inner join
Answer : D

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

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

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

17. 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

18. 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

19. 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

20. Data independence means
A. data is defined separately and not included in programs.
B. programs are not dependent on the physical attributes of data
C. programs are not dependent on the logical attributes of data
D. both B and C
Answer : D

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

22. 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

23. DFD stands for
A. Data Flow Document
B. Data File Diagram
C. Data Flow Diagram
D. Non of the above
Answer : C

24. 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

25. 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

26. Which of the following addressing modes permits relocation without any change over in the code?
A. Indirect addressing
B. Indexed addressing
C. PC relative addressing
D. Base register addressing
Answer : B

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

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

31. ______ keyword is used to find the number of values in a column.
A. TOTAL
B. ADD
C. COUNT
D. SUM
Answer : C

32. _____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

33. _______ product was acquired by Informix, integrated into its RDBMS and introduced as the Informix Universal Server an ORDBMS.
A. Star
B. llustar
C. SQL
D. Cygnus
Answer : B

34. A data type or format is specified for each _________
A. Relation
B. Tuple
C. Database
D. Domain
Answer : B

35. 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

36. The rule that a value of a foreign key must appear as a value of some specific table is called a
A. Referential constraint.
B. Index.
C. Integrity constraint.
D. Functional dependency.
Answer : A

37. A table can have only one
A. Secondary key
B. Alternate key
C. Unique key
D. Primary key
Answer : D

38. Given the following relation S(SNO,SNAME,CITY) write a query to update the value of CITY to KANPUR for the supplier S1.
A. UPDATE S CITY = KANPUR WHERE SNO=S1
B. UPDATE S SET CITY = KANPUR FOR SNO=S1
C. UPDATE S SET CITY = KANPUR WHERE SNO=S1
D. UPDATE S RENAME CITY = KANPUR WHERE SNO=S1
Answer : C

39. 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

40. 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

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

42. 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

43. In an E-R diagram double lines indicate
A. Total participation.
B. Multiple participation.
C. Cardinality N.
D. None of the above.
Answer : A

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

45. 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

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 f the above
Answer : C

47. 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

48. Which of the following relational algebraic operations is not from set theory?
A. Union
B. Intersection
C. Cartesian Product
D. Select
Answer : D

49. A list consists of last names, first names, addresses and pin codes. If all people in the list have the same last name and same pin code a useful key would be
A. the pin code
B. the last name
C. the compound key first name and last name
D. Tr from next page
Answer : C

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