May 23, 2017 · MapReduce is a method to process vast sums of data in parallel without requiring the developer to write any code other than the mapper and reduce functions. The map function …

MapReduce's use of input files and lack of schema support prevents the performance improvements enabled by common database system features such as B-trees and hash …

Dec 10, 2015 · By default mapreduce picks only one reducer which will be the issue for most of the scenarios. Either you can change the code by setting number of reducers to a higher value …

Sep 12, 2012 · MapReduce is a framework originally developed at Google that allows for easy large scale distributed computing across a number of domains. Apache Hadoop is an open …

Also your use of MapReduce paradigm for the given problem is incorrect, using a single map function and multiple "different" reduce function makes no sense, it shows that you are just …

Apr 8, 2023 · I'm trying to write a MapReduce program that can read an input file and write the output to another text file. I'm planning to use the BufferedReader class for this. But I don't …

Mar 3, 2014 · Then, the MapReduce job stops at the map phase, and the map phase does not include any kind of sorting (so even the map phase is faster). Tom White has been an Apache …

Jul 23, 2013 · How can I sort in decreasing order the reducer output by value? I'm developing an application that must return top listened songs. Thus songs must be ordered by the number of …

Oct 22, 2013 · It is against the MapReduce paradigm and will generally prevent parallelism. If you absolutely must pass information between the Map and Reduce phase, and you cannot do it …

Nov 26, 2021 · Thanks @Mortz. It works with the combiner but doesn't without. It's my understanding that the whole MapReduce code should work with or without the Combiner …