I often see that people mention the Hadoop MapReduce in their CV but are not clear about the fundamental principles behind MapReduce.
If I ask if Hadoop MapReduce is closer to Java map or Array.sort, the quick answer is Java map which is wrong.
So, I strongly suggest everyone to go thru the following videos:
Understanding Sorting:
Understanding Distributed Sorting:
https://cloudxlab.com/assessment/displayslide/190/mapreduce-thinking-in-mr-programatic-sql?course_id=68&playlist_id=341
https://cloudxlab.com/assessment/displayslide/189/mapreduce-thinking-in-mr-unix-pipeline?course_id=68&playlist_id=341
https://cloudxlab.com/assessment/displayslide/188/mapreduce-thinking-in-mr-external-sort?course_id=68&playlist_id=341
Understanding MR:
https://cloudxlab.com/assessment/displayslide/187/mapreduce-understanding-the-paradigm?course_id=68&playlist_id=341