Explanation:InputDataStream is used to read data from file. 2. Point out the correct statement :
A. The framework groups Reducer inputs by keys
B. The shuffle and sort phases occur simultaneously i.e. while outputs are being fetched they are merged
C. Since JobConf.setOutputKeyComparatorClass(Class) can be used to control how intermediate keys are grouped, these can be used in conjunction to simulate secondary sort on values
D. All of the mentioned
Answer:A
Explanation:InputDataStream is used to read data from file. 2. Point out the correct statement :
A. The framework groups Reducer inputs by keys B. The shuffle and sort phases occur simultaneously i.e. while outputs are being fetched they are merged C. Since JobConf.setOutputKeyComparatorClass(Class) can be used to control how intermediate keys are grouped, these can be used in conjunction to simulate secondary sort on values D. All of the mentioned
Explanation:If equivalence rules for keys while grouping the intermediates are different from those for grouping keys before reduction, then one may specify a Comparator. 3. ______________ is method to copy byte from input stream to any other stream in Hadoop.