I think Hadoop and MapReduce are suitable, Because there are many references for learning these.

https://neo4j.com/

Graph Database : Neo4j

Dear Amol C Adamuthe,

If it is related to Big Data Analytics, I recommend you to use HBase or Cassandra.

https://hbase.apache.org/

https://www.tutorialspoint.com/hbase/

http://cassandra.apache.org/

It would depend what it is for and what the students know already. How easy something is shouldn't really be the main driver for selecting study topics. I have used Neo4j, as graph databases are so very different from any other type of data store. Students also like it because it is very visual. For a more "traditional" NoSQL database, I have selected MongoDB.

Dear Dr. Amol.

I think it depends on the main subject.

Regarding Distributed and Parallel Computing the best is Haddop and MapReduce/HDFS.

For working with data preparation, segmentation and joining, the best is Spark/Scala

For data mining and knowledge discovery R language, Python, Spark and Mahout.

I find that many of my undergraduate students find it easy to learn and use MongoDB.

Thank you all for your guidance.

MongoDB