Why we cannot do aggregation (addition) in a mapper? Why we require reducer for that?
No Answer is Posted For this Question
Be the First to Post Answer
What is a Record Reader in hadoop?
How is hadoop different from other data processing tools?
What is the purpose of RawComparator interface?
Which are the two types of 'writes' in HDFS?
What is the functionality of jobtracker in hadoop? How many instances of a jobtracker run on hadoop cluster?
What is MapFile?
Why is hadoop faster?
What is Rack Awareness in Apache Hadoop?
Have you ever used Counters in Hadoop. Give us an example scenario?
Explain the wordcount implementation via hadoop framework ?
Explain the hadoop configuration files at present?
What is Input Split in hadoop?
Apache Hadoop (394)
MapReduce (354)
Apache Hive (345)
Apache Pig (225)
Apache Spark (991)
Apache HBase (164)
Apache Flume (95)
Apache Impala (72)
Apache Cassandra (392)
Apache Mahout (35)
Apache Sqoop (82)
Apache ZooKeeper (65)
Apache Ambari (93)
Apache HCatalog (34)
Apache HDFS Hadoop Distributed File System (214)
Apache Kafka (189)
Apache Avro (26)
Apache Presto (15)
Apache Tajo (26)
Hadoop General (407)