Conventions used

There are a number of text conventions used throughout this book.

Code in text: Indicates code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles. Here is an example: "The preceding code block creates a Spark DataFrame and displays the first 1,000 records. Now, let's run some code with the collect() function."

A block of code is set as follows:

airlines_1987_to_2008.select('Year').distinct().collect()

Bold: Indicates a new term, an important word, or words that you see onscreen. For instance, words in menus or dialog boxes appear in bold. Here is an example: "Click on Spark Jobs under this command and select View next to the second job. This opens up the job page in Spark UI."

Tips or Important Notes

Executor slots are also called cores or threads.