Hadoop MCQ Questions Answers

1. Which one is the correct syntax for the command used for setting replication for an existing file in Hadoop WebHDFS REST API?

2. In Pig, which of the following types of join operations can be performed using the Replicated join? i) Inner join ii) Outer join iii) Right-outer join iv) Left-outer join

3. Which one is the master process that accepts the job submissions from the clients and schedule the tasks to run on worker nodes?

4. Which environment variable is used for determining the Hadoop cluster for Pig, in order to run the MapReduce jobs?

5. Which HDFS command is used for checking inconsistencies and reporting problems with various files?

6. Which command is used to view the content of a file named /newexample/example1.txt?

7. In the Hadoop architecture, which component is responsible for planning and execution of a single job?

8. Which interface is used for accessing the Hive metastore?

9. What is the function of the following Hadoop command? du

10. In Hadoop, HDFS snapshots are taken for which of the following reasons? i) For providing protection against user error. ii) For providing backup. iii) For disaster recovery. iv) For copying data from data nodes.

11. Before being inserted to a disk, the intermediate output records emitted by the Map task are buffered in the local memory, using a circular buffer. Which of the following properties is used to configure the size of this circular buffer?

12. Which interface can decrease the amount of memory required by UDFs, by accepting the input in chunks?

13. Which Hive clause should be used for imposing a total order on the query results?

14. Which Hive command is used for creating a database named MyData?

15. Which option is the function of the following Hadoop command? -a

16. In which Pig execution mode, a Java program is capable of invoking Pig commands by importing the Pig libraries?

17. Which of the given Pig data types has the following characteristics? i) It is a collection of data values. ii) These data values are ordered and have a fixed length.

18. Which function is performed by the Scheduler of Resource Manager in the YARN architecture?

19. Which are the characteristics of the UNION operator of Pig?

20. Which operator is necessary to be used for theta-join?

21. Which one is the correct line command syntax of the Hadoop streaming command?

22. Which statement is correct about the Hive joins?

23. Which one is used for changing the group of a file?

24. Suppose you need to select a storage system that supports Resource Manager High Availability (RM HA). Which of the following types of storage should be selected in this case?

25. Which statement is correct about the Hadoop file system namespace?

26. Which Hadoop command is used for creating a file of zero length?

27. Consider an input file named abc.dat.txt with default block size 128 MB. Which one is the correct command that will upload this file into an HDFS, with a block size of 512 MB?

28. What is the function of the following Configuration property of YARN's Resource Manager? yarn.resourcemanager.ha.id

29. Which two of the following are the correct differences between MapReduce and traditional RDBMS?

30. Which statements is correct about YARN's Web Application Proxy?

31. Which two parameters of the Hadoop streaming command are optional?

32. Which command is used for setting an environment variable in a streaming command?

33. Which are the advantages of the disk-level encryption in HDFS?

34. For a file named abc, which of the following Hadoop commands is used for setting all the permissions for owner, setting read permissions for group, and setting no permissions for other users in the system?

35. Which permission level is NOT allowed in HDFS authorization?

36. Which join operations are NOT supported by Hive?

37. Which command is used for creating a keytab file used in Kerberos authentication?

38. Which one is the advanced server-side configuration property of YARN that is used for enabling the deletion of aged data present in the timeline store?

39. In order to execute a custom, user-built JAR file, the jar command is used. Which of the following is the correct syntax of this command?

40. Which YARN command is used for overwriting the default Configuration directory ${HADOOP_PREFIX}/conf?

41. Which HiveQL command is used for printing the list of configuration variables overridden by Hive or the user?

42. Which of the given options is the correct function of the following HiveQL command? !

43. Which are the functions of Hadoop? i) Data Search ii) Data Retention iii) Recommendation systems iv) Analytics

44. Which configuration property of YARN's Resource Manager is used for specifying the host:port for clients to submit jobs?

45. Which HDFS command is used for setting an extended attribute name and value for a file or a directory?

46. Which Pig commands is/are used for sampling a data and applying a query on it?

47. Which one is the correct syntax for the docs Maven profile that is used for creating documentation in Hadoop Auth?

48. In case of service-level authorization in Hadoop, which of the following properties is used for determining the ACEs used for granting permissions for the DataNodes to communicate and access the NameNode?

49. What is the default value of the following security configuration property of the YARN architecture? yarn.timeline-service.delegation.token.renew-interval

50. While configuring HTTP authentication in Hadoop, which of the following is set as the value of the 'hadoop.http.filter.initializers' property?

51. Which of the following HDFS shell commands is used for setting a group for a particular file or directory?

52. Which are the required command line arguments for the oev command of HDFS?

53. Which one is the Hadoop directory service that stores the metadata related to the files present in the cluster storage?

54. Which function is NOT performed by the InputFormat class for a MapReduce Hadoop job?

55. Which command is used for distributing an excluded file to all the Namenodes?

56. While accessing a Hadoop Auth protocol URL using curl, which command options are used for storing and sending HTTP cookies?

57. What is the default value of the hadoop.http.authentication.token.validity property that is used in case of authentication via HTTP interface?

58. In case of a Multiquery execution, which code indicates retrievable errors for an execution?

59. Which Hadoop command is used for copying a source path to stdout?

60. Which Hadoop DFSAdmin command generates a list of DataNodes?

61. Which are NOT the properties of the app (Application) object of NodeManager REST API?

62. Which one is the correct data type of the 'totalMB' element of the clusterMetrics object used in the YARN ResourceManager REST API?

63. Which object is used by the RecordReader class for reading data from an InputSplit class?

64. Which one is the correct syntax for resetting the space quota for directories in HDFS?

65. Which operator is used for un-nesting the nested tuples and bags?

66. Which query is valid?

67. Examine the data in the EMPLOYEES table given below: LAST_NAME DEPARTMENT_ID SALARY ALLEN 10 3000 MILLER 20 1500 King 20 2200 Davis 30 5000 Which of the following Subqueries work?

68. Which of the following are false for batches (batch commands)?

69. View the following Create statement: 1 Create table Pers 2(EmpNo Int not null, 3 EName Char not null, 4 Join Datetime not null, 5 Pay Smallmoney) Which line contains an error?

70. The IF UPDATE (column_name) parameter in a trigger definition will return TRUE in case of an INSERT statement being executed on the triggered table:

71. Consider the following table structure of students: rollno int name varchar(20) course varchar(20) What will be the query to display the courses in which the number of students enrolled is more than 5?

72. Consider the following tables: Books ------ BookId BookName AuthorId SubjectId PopularityRating (the popularity of the book on a scale of 1 to 10) Language (such as French, English, German etc) Subjects --------- SubjectId Subject (such as History, Geography, Mathematics etc) Authors -------- AuthorId AuthorName Country What is the query to determine how many books have been written on each subject. Displaying Name of Subject and count of the Books?

73. Consider the following tables: Books ------ BookId BookName AuthorId SubjectId PopularityRating (the popularity of the book on a scale of 1 to 10) Language (such as French, English, German etc) Subjects --------- SubjectId Subject (such as History, Geography, Mathematics etc) Authors -------- AuthorId AuthorName Country What is the query to determine the names of the Authors who have written more than 1 book?

74. Which one is not a SQL operator?

75. Which ones are aggregate functions in SQL?

76. Which is not (a) valid binary datatype in SQL Server?

77. What is the correct SQL syntax for selecting all the columns where the 'LastName' is alphabetically between (and including) 'Hansen' and 'Pettersen'?

78. Evaluate the following SQL statement: SELECT e.employee_id, (.15* e.salary) + (.5 * e.commission_pct) + (s.sales_amount * (.35 * e.bonus)) AS CALC_VALUE FROM employees e, sales s WHERE e.employee_id = s.emp_id; What will happen if all the parentheses are removed from the calculation?

79. State which of the following are true

80. Consider the query: SELECT name FROM Student WHERE name LIKE '_a%'; Which names will be displayed?

81. Which one is not a valid Arithmetic operator in SQL Server?

82. Does SQL Server support user-defined datatypes?

83. Which one is not a column property?

84. Which of the following is not a control statement?

85. Which one is an invalid statement for manipulation of binary data?

86. A table has following values for its department field: marketing, production, production, sales, NULL, NULL, Marketing, Null What will the following query return: Select distinct(department) from employees

87. ___________ is the highest level of a transaction isolation implemented by SQL Server.

88. Which one must be specified in every DELETE statement?

89. What does referential integrity (also called relational integrity) prevent?

90. Which one is true with reference to Triggers?

91. Consider the transaction: Begin Transaction Create table A ( x smallint , y smallint ) Create table B ( p smallint , q smallint ) Update A set x=600 where y > 700 Update B set p=78 where q=99 If @@ error != 0 Begin RollBack Transaction Return End Commit Transaction Select the correct option:

92. You should avoid the use of cursors because:

93. How can you change 'Hansen' into 'Nilsen' in the LastName column in the PersonsTable?

94. A cursor is a pointer that identifies a specific working row within a set

95. What is the numeric range that is supported by the datatype tinyint?

96. Which constraints can be used to enforce the uniqueness of rows in a table?

97. Examine the code given below: SELECT employee_id FROM employees WHERE commission_pct=.5 OR salary > 23000 Which of the following statements is correct with regard to this code?

98. You are maintaining data for its products in the Products table, and want to see the products that are 50 or more in number, far from the minimum stock limit. The structure of the Products table is:

99. The AND operator displays a row if ANY conditions listed are true. The OR operator displays a row if ALL of the conditions listed are true

100. Examine the query:- select (2/2/4) from tab1; where tab1 is a table with one row. This would give a result of: