Hadoop Map/Reduce with database

Question

I am very new to hadoop , learned about its map/reduce functionality a bit , understands it wordcount demo , but not get the actual use of hadoop map/reduce in relate to database specific computations. That is not getting correct way that how map/reduce help me in some computations or database specific processings. Can anyone provide me a link or some guide which will help me in getting what is the best use and which senerio I can implement to better understand Hadoop map/reduce part.

Answer 1

Hadoop provides with a couple of Input and Outputs formats. The base InputFormat and the OutputFormat classes can be extended for customized Input/Output formats.

DBInputFormat/DBOutputFormat come with Hadoop. Here is the documentation from Cloudera on using the MapReduce with Database.