KEYIN- The type of the input key.
VALUEIN- The type of the input value.
KEYOUT- The type of the output key.
public abstract class TableReducer<KEYIN,VALUEIN,KEYOUT> extends org.apache.hadoop.mapreduce.Reducer<KEYIN,VALUEIN,KEYOUT,org.apache.hadoop.io.Writable>
Reducerclass to add the required key and value input/output classes. While the input key and value as well as the output key can be anything handed in from the previous map phase the output value must be either a
Deleteinstance when using the
This class is extended by
IdentityTableReducer but can also be
subclassed to implement similar features or any custom code needed. It has
the advantage to enforce the output value to a specific basic type.
|Constructor and Description|
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