Hadoop has a library class, org.apache.hadoop.mapred.lib.FieldSelectionMapReduce, that effectively allows you to process text data like the unix ______ utility.

Hadoop has a library class, org.apache.hadoop.mapred.lib.FieldSelectionMapReduce, that effectively allows you to process text data like the unix ______ utility.
Cut
Well Done. Your Answer is Correct Keep it Up! Explanation: The map function defined in the class treats each input key/value pair as a list of fields.
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______________ class allows the Map/Reduce framework to partition the map outputs based on certain key fields, not the whole keys.

______________ class allows the Map/Reduce framework to partition the map outputs based on certain key fields, not the whole keys.
KeyFieldBasedPartitioner
Well Done. Your Answer is Correct Keep it Up! Explanation: The primary key is used for partitioning, and the combination of the primary and secondary keys is used for sorting.
KeyFieldPartitioner
KeyFieldBased
None of the Option is Correct

Point out the wrong statement.

Point out the wrong statement.
To use Aggregate, simply specify “-mapper aggregate”
Excellent ! Your Answer is Correct. Explanation: To use Aggregate, simply specify “-reducer aggregate”:
None of the Options is Correct
Aggregate allows you to define a mapper plugin class that is expected to generate “aggregatable items” for each input key/value pair of the mappers
Hadoop has a library package called Aggregate

Point out the correct statement.

Point out the correct statement.
You can specify any executable as the mapper and/or the reducer
Excellent ! Your Answer is Correct. Explanation: If you do not specify an input format class, the TextInputFormat is used as the default.
You cannot supply a Java class as the mapper and/or the reducer
The class you supply for the output format should return key/value pairs of Text class
All Options are Correct

How are keys and values presented and passed to the reducers during a standard sort and shuffle phase of MapReduce?

How are keys and values presented and passed to the reducers during a standard sort and shuffle phase of MapReduce?
Keys are presented to reducer in sorted order; values for a given key are not sorted.
Excellent ! Your Answer is Correct.
Keys are presented to reducer in sorted order; values for a given key are sorted in ascending order.
Keys are presented to a reducer in random order; values for a given key are not sorted.
Keys are presented to a reducer in random order; values for a given key are sorted in ascending order.

When is the earliest point at which the reduce method of a given Reducer can be called?

When is the earliest point at which the reduce method of a given Reducer can be called?
Not until all mappers have finished processing all records.
Excellent ! Your Answer is Correct.
As soon as a mapper has emitted at least one record.
As soon as at least one mapper has finished processing its input split.
It depends on the InputFormat used for the job.
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