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: "When a program is run on a Spark shell, it is called the driver program with the user's main method in it."

A block of code is set as follows:

Scala> sc.parallelize(List(2, 3, 4)).count()
res0: Long = 3
Scala> sc.parallelize(List(2, 3, 4)).collect()
res1: Array[Int] = Array(2, 3, 4)
Scala> sc.parallelize(List(2, 3, 4)).first()
res2: Int = 2
Scala> sc.parallelize(List(2, 3, 4)).take(2)
res3: Array[Int] = Array(2, 3)

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: "It also allows users to source data using Data Source API from the data sources that are not supported out of the box (for example, CSV, Avro HBase, Cassandra, and so on.)"

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.