There are many blogs explaining how HyperLogLog works. We even have a few open-source implementations of HyperLogLog (in Java, Python, C++). Documentation on writing UDAF for Apache Hive is readily ...

Iam Currently Working on Hive0.14 - MonogDB 2.6.3, as per the steps I builded successfully and copied hive-mongo-0.0.3.jar,guava-r06.jar,mongo-2.6.3.jar into hive ...