what is identity mapper


50 Mapreduce Interview Questions and Answers Part – 1 10

A few of the hadoop Mapreduce Interview questions and answers are presented in this post. These are suitable for both beginners and experienced mapreduce developers. Mapreduce Interview Questions and Answers for Freshers: 1.  What is Mapreduce ? Mapreduce is a framework for processing  big data (huge data sets using a large number of commodity computers). It processes the data in two phases namely Map and Reduce phase. This programming model is […]


Predefined Mapper and Reducer Classes

Hadoop provided some predefined Mapper and Reducer classes in its Java API and these will be helpful in writing simple or default mapreduce jobs. A few among the entire list of predefined mapper and reducer classes are provided below. Identity Mapper Identity Mapper is the default Mapper class provided by hadoop and this will be picked automatically when no mapper is specified in Mapreduce driver class. Identity Mapper class implements […]


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Dharmeswaran ETL / Hadoop Developer Spark Nov 2016 September 21, 2017

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