Big Data Online Practice Test - 9

Q. A developer was faced,with a Mapreduce concept,of spilling,in an exam. He was told, to mark the following statements,as Yes or No:
1) If the size,of the Mapper task output,is 60Mb,then,spilling of data,to the disc,starts taking place.(for a total 100Mb size of circular buffer)
2) Mapper function stops,when,the spilling of data,to discs,happens.
3) When the size,of the Mapper task output,reaches 100Mb(where 100Mb is also the circular buffer size),then,spilling of data,to the disc starts.
4) Mapper function stops,when mapper output rate,is greater than,the spilling rate.
Choose the correct answer.

Q. A developer,was playing around,with different Hadoop commands. At one point,he received the output as:
a) 2017-10-22 04:33:04
b) 1
Guess the Hadoop commands,he must have executed,to get the output.

Q. If the tennis player names collection, is:
players:"Federer,Djokovic,Nadal,Potro"
What is the output, after the following query is executed:

 
db.tennis.update({_id:3},{$pop:{names:-1}});

Mark the correct option.

Q. In a test,freshers were provided,following code snippets:

        
import Array._
object TestArray {
   def main(args: Array[String]) {
      var concat1 = Array(0.8,1.4, 2.3, 5.5)
      var concat2 = Array(7.6, 8.1,1.1, 1.4)      
      var concat3 =  concat( concat1, concat2)

      var rangedisplay = range(8, 20, 3)
  }
    

What is the output,when concat3 and rangedisplay are printed.
Mark the correct option.

Q. Consider the following code snippet:

 
Hive>CREATE EXTERNAL TABLE portinfoexternal(portid INT,portname STRING)
     Row format delimited
     Fields terminated by '\t'
     LOCATION '/usr/porthive/portdetailsexternal;
What is true about it?

1) This type of table is loosely coupled.
2) If the location,is not specified,at the time of creation,data can be loaded manually.
3) External tables,do not allow,many schema's to be created,for the data stored.
4) If the files,are not needed,outside hive, one can go for an external table.
Mark the correct option.

Q. A developer was learning ,about different types of databases. Mark,which of the following descriptions,applies to Cassandra and RDMBS:
1) This kind of database has a flexible schema.
2) Here, table is a list, of nested key-value pairs.
3) The distribution of data,is manual.
4) Database is slow,when it comes to storage or data transfer.

Q. A developer was told,to sort the "TravelDocs" relation,based on the AuthorName.
If,the relation,is loaded as:
X = load 'docs/traveldocs/info.tsv' as (id:int,authorname:chararray,info:chararray);
Then,which of the following,is a correct syntax,to sort by author name.

Q. In the new sprint cycle, a developer was told to make changes,such that,JVM would be reused,any number of times,whenever a new mapper task,is launched.
Which of the following, is a correct way,of doing the same?

Q. Map the descriptions,that match,the different Hadoop modes.
Stand-alone (S), Pseudo(P) and Fully distributed (F).
1) Every Hadoop daemon, runs,in a distinct Java process.
2) One node,acts as a Master node,Data node, Job tracker, Task tracker
3) Spread across many nodes, the data is stored and processed.
4) Local file system,is used,for input and output.
Mark the correct option.

Q. In a quiz, freshers were told to mark,which of the statements,related to MongoDb,are true/false.
1) MongoDb supports,dynamic schema design.
2) It is a key-value,store oriented design.
3) It does not allows,query joins,between collections.
4) MongoDb is supported, by Python, but not Perl.
Mark the correct answer.