HDPCD Exam Training Practice Tests (Hortonworks Data Platform Certified Developer)]

Question 1

You want to count the number of occurrences for each unique word in the supplied input data. You've decided to implement this by having your mapper tokenize each word and emit a literal value 1, and then have your reducer increment a counter for each literal 1 it receives. After successful implementing this, it occurs to you that you could optimize this by specifying a combiner. Will you be able to reuse your existing Reduces as your combiner in this case and why or why not?

A. No, because the sum operation in the reducer is incompatible with the operation of a Combiner. B. No, because the Combiner is incompatible with a mapper which doesn't use the same data type for both the key and value. C. Yes, because the sum operation is both associative and commutative and the input and output types to the reduce method match. D. Yes, because Java is a polymorphic object-oriented language and thus reducer code can be reused as a combiner. E. No, because the Reducer and Combiner are separate interfaces.

Correct Answer: C

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Question 2

Review the following data and Pig code.
M,38,95111 F,29,95060 F,45,95192 M,62,95102 F,56,95102
A = LOAD 'data' USING PigStorage('.') as (gender:Chararray, age:int, zlp:chararray);
B = FOREACH A GENERATE age;
Which one of the following commands would save the results of B to a folder in hdfs named myoutput?

A. STORE A INTO 'myoutput' USING PigStorage(','); B. STORE B INTO 'myoutput'; C. DUMP B using PigStorage('myoutput'); D. DUMP B INTO 'myoutput';

Correct Answer: B

Question 3

Can you use MapReduce to perform a relational join on two large tables sharing a key? Assume that the two tables are formatted as comma-separated files in HDFS.

A. Yes, but only if one of the tables fits into memory B. Yes, so long as both tables fit into memory. C. No, but it can be done with either Pig or Hive. D. No, MapReduce cannot perform relational operations. E. Yes.

Correct Answer: E

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Question 4

You wrote a map function that throws a runtime exception when it encounters a control character in input data. The input supplied to your mapper contains twelve such characters totals, spread across five file splits. The first four file splits each have two control characters and the last split has four control characters.
Indentify the number of failed task attempts you can expect when you run the job with mapred.max.map.attempts set to 4:

A. You will have seventeen failed task attempts B. You will have twelve failed task attempts C. You will have twenty failed task attempts D. You will have forty-eight failed task attempts E. You will have five failed task attempts

Correct Answer: C

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Question 5

You have a directory named jobdata in HDFS that contains four files: _first.txt, second.txt, .third.txt and #data.txt. How many files will be processed by the FileInputFormat.setInputPaths () command when it's given a path object representing this directory?

A. Four, all files will be processed B. None, the directory cannot be named jobdata C. Three, the pound sign is an invalid character for HDFS file names D. One, no special characters can prefix the name of an input file E. Two, file names with a leading period or underscore are ignored

Correct Answer: E

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Question 6

To use a lava user-defined function (UDF) with Pig what must you do?

A. Register the JAR file containing the UDF B. Pass arguments to the constructor of UDFs implementation class C. Define an alias to shorten the function name D. Put the JAR file into the user's home folder in HDFS

Correct Answer: A

Question 7

Which one of the following statements is true about a Hive-managed table?

A. Records can only be added to the table using the Hive INSERT command. B. Hive dynamically defines the schema of the table based on the FROM clause of a SELECT query. C. Hive dynamically defines the schema of the table based on the format of the underlying data. D. When the table is dropped, the underlying folder in HDFS is deleted.

Correct Answer: D

Hortonworks Data Platform Certified Developer - HDPCD Exam Practice Test