Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "Spark expects Java to be installed and the JAVA_HOME environment variable to be set."

A block of code is set as follows:

  [{ "firstName" : "Bill", "lastName": "Clinton", "age": 70 }
          {"firstName": "Barack","lastName": "Obama", "age": 55}]

Any command-line input or output is written as follows:

 scala> val people = spark.sql("select * from person")

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Click on Create cluster and select the last option in the Applications option box."

Warnings or important notes appear in a box like this.

Tips and tricks appear like this.