Conventions

In this book, you will find a number of styles of text 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: " By using the pg_stat_statements view, we learn quite a bit about our PostgreSQL cluster."

A block of code is set as follows:

CREATE VIEW v_current_activity AS
SELECT *
  FROM pg_stat_activity
 WHERE state != 'idle';

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

CREATE VIEW v_running_queries AS
SELECT pid, now() - query_start AS duration, query
  FROM pg_stat_activity
 WHERE state != 'idle';

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

rsync -av --progress --delete source-server:/db/pgdata/ \     
       /db/pgdata

New terms and important words are shown in bold. Words that you see on the screen, in menus or dialog boxes for example, appear in the text like this: "Clicking the Next button moves you to the next screen."

Warnings or important notes appear in a box like this.

Tips and tricks appear like this.