What is Reducer in Hadoop?
What are the most common InputFormats in Hadoop?
Explain InputSplit in Hadoop?
What is the purpose of RecordReader in hadoop?
What is Combiner in Hadoop?
If no custom partitioner is defined in Hadoop then how is data partitioned before it is sent to the reducer?
Why aggregation cannot be done in Mapper?
Explain map-only job?
What is KeyValueTextInputFormat in Hadoop?
What happen if number of reducer is set to 0 in Hadoop?
What is TextInputFormat in Hadoop?
What is purpose of RecordWriter in Hadoop?
What are the most common OutputFormat in Hadoop?
What is LazyOutputFormat in Hadoop?
What is Identity reducer?