Hortonworks Hadoop 2.0 Certification exam for Pig and Hive Developer 認定 Apache-Hadoop-Developer 試験問題:

1. You need to create a job that does frequency analysis on input data. You will do this by writing a Mapper that uses TextInputFormat and splits each value (a line of text from an input file) into individual characters. For each one of these characters, you will emit the character as a key and an InputWritable as the value. As this will produce proportionally more intermediate data than input data, which two resources should you expect to be bottlenecks?

A) Processor and RAM
B) Processor and disk I/O
C) Disk I/O and network I/O
D) Processor and network I/O

2. Given the following Hive command:
INSERT OVERWRITE TABLE mytable SELECT * FROM myothertable;
Which one of the following statements is true?

A) A new table named mytable is created, and the contents of myothertable are copied into mytable
B) Any existing data in mytable will be overwritten
C) The statement is not a valid Hive command
D) The contents of myothertable are appended to mytable

3. Which best describes what the map method accepts and emits?

A) It accepts a single key-value pairs as input and can emit any number of key-value pair as output, including zero.
B) It accepts a list key-value pairs as input and can emit only one key-value pair as output.
C) It accepts a single key-value pair as input and emits a single key and list of corresponding values as output.
D) It accepts a single key-value pairs as input and can emit only one key-value pair as output.

4. Examine the following Hive statements:

Assuming the statements above execute successfully, which one of the following statements is true?

A) Each reducer generates a file sorted by age
B) The SORT BY command causes only one reducer to be used
C) The output of each reducer is only the age column
D) The output is guaranteed to be a single file with all the data sorted by age

5. All keys used for intermediate output from mappers must:

A) Implement WritableComparable.
B) Be a subclass of FileInputFormat.
C) Implement a splittable compression algorithm.
D) Implement a comparator for speedy sorting.
E) Override isSplitable.

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