008 mapreduce hadoop customization secondary sort

This is one of the lecture videos produced for the course held "distributed data management" at TU Kaiserslautern in Summer Term 2021, by the databases and information systems lab (dbis.cs.rptu.de/) headed by Prof. Sebastian Michel, at the department of computer science.
The lecture slides, which provide the basis of the videos, are to some extent based on several sources, like the slides on Data Streams by Jennifer Widom, Johannes Gehrke, and Minos Garofalakis, and the slides on Cloud Computing Matthias Bender created to a large extent when giving a guest lecture. In hopefully all cases the sources should be mentioned in the slides or beginning of chapters. Thanks to all! Please contact Prof. Michel ([e-mail]) if you disagree with the content published here or feel not mentioned here. And yes, some of the slides I also created on my own.