In order for this book to be useful, you need at least access to a PostgreSQL client that is allowed to execute queries on a server. Ideally, you'll also be the server administrator. Full client and server packages for PostgreSQL are available for most popular operating systems at http://www.postgresql.org/download/. All the examples here are executed on Command Prompt, usually running the psql program. This makes them applicable to most platforms. It's straightforward to do many of these operations using a GUI tool for PostgreSQL instead, such as the pgAdmin program. Some scripts that are written in the bash scripting language are provided.

You can download the example code files for this book from your account at www.packtpub.com. If you purchased this book elsewhere, you can visit www.packtpub.com/support and register to have the files emailed directly to you.

You can download the code files by following these steps:

1. Log in or register at www.packtpub.com.
2. Select the SUPPORT tab.
3. Click on Code Downloads & Errata.
4. Enter the name of the book in the Search box and follow the onscreen instructions.

Once the file is downloaded, please make sure that you unzip or extract the folder using the latest version of:

• WinRAR/7-Zip for Windows
• Zipeg/iZip/UnRarX for Mac
• 7-Zip/PeaZip for Linux

The code bundle for the book is also hosted on GitHub at https://github.com/PacktPublishing/PostgreSQL-10-High-Performance. In case there's an update to the code, it will be updated on the existing GitHub repository.

We also have other code bundles from our rich catalog of books and videos available at https://github.com/PacktPublishing/. Check them out!

We also provide a PDF file that has color images of the screenshots/diagrams used in this book. You can download it here: http://www.packtpub.com/sites/default/files/downloads/PostgreSQL10HighPerformance_ColorImages.pdf.

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

CodeInText: 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 sync here is to try and flush all the data to the disk before we just blow away the caches."

A block of code is set as follows:

for each outer row:
  for each inner row:
     if join condition is true:
       output combined row

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

EXPLAIN ANALYZE SELECT * FROM orders WHERE customerid IN (SELECT customerid FROM customers WHERE customerid=1000 OR customerid=2000);

Bold: Indicates a new term, an important word, or words that you see onscreen. For example, words in menus or dialog boxes appear in the text like this. Here is an example: "HD Tune includes a Random Access test that gives its results in terms of the standard IOPS figure, at various block sizes."