I am practicing MapReduce and going through some code. My question is, why do we use the extends keyword. i.e MyMapper extends Mapper. extends is meant for the keyword of inheritance in Java, then why we use it here?
The Mapper class belongs to package org.apache.hadoop.mapreduce and map function is a function of Mapper class so whenever you want to use any function of Mapper class you will be extending mapper class as parent class where MyMapper acts as a child class.
The "distinct" statement is very simple. It ...READ MORE
Yes, InputFormatClass and OutputFormatClass are independent of ...READ MORE
In simple explanation,
When specify SPLIT_BY only ...READ MORE
The command sqoop help lists the tools ...READ MORE
Firstly you need to understand the concept ...READ MORE
org.apache.hadoop.mapred is the Old API
org.apache.hadoop.mapreduce is the ...READ MORE
put <localSrc> <dest>
copyFr ...READ MORE
In your case there is no difference ...READ MORE
Try this and see if it works:
public ...READ MORE
The combiner class is not required in ...READ MORE
Already have an account? Sign in.