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Practical Data Analysis

Practical Data Analysis - Second Edition

By : Hector Cuesta, Dr. Sampath Kumar
3.5 (2)
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Practical Data Analysis

Practical Data Analysis

3.5 (2)
By: Hector Cuesta, Dr. Sampath Kumar

Overview of this book

Beyond buzzwords like Big Data or Data Science, there are a great opportunities to innovate in many businesses using data analysis to get data-driven products. Data analysis involves asking many questions about data in order to discover insights and generate value for a product or a service. This book explains the basic data algorithms without the theoretical jargon, and you’ll get hands-on turning data into insights using machine learning techniques. We will perform data-driven innovation processing for several types of data such as text, Images, social network graphs, documents, and time series, showing you how to implement large data processing with MongoDB and Apache Spark.
Table of Contents (16 chapters)
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Using MapReduce with MongoDB

MongoDB provides us with a MapReduce command, and in the following diagram we can observe the life cycle of the MapReduce process in MongoDB. We start with a Collection or a Query; each document in the collection will call the map function. Then, with the emit function, we will create an intermediate hash-map (see the following diagram) with a list of pairs (key-value).

Next, the reduce function will iterate the intermediate hash-map and will apply some operations to all values of each key. Finally, the process will create a brand new collection with the output. The map/reduce functions in MongoDB will be programmed with JavaScript:

Using MapReduce with MongoDB

Tip

Find the reference documentation for MapReduce with MongoDB from the following link:

http://docs.mongodb.org/manual/core/map-reduce/

Map function

The map function will call the emit function one or more times (see the previous diagram). We can access all the attributes of each document in the collection with the this keyword. The...

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