Chapter 39. Triggers

Table of Contents

39.1. Overview of Trigger Behavior
39.2. Visibility of Data Changes
39.3. Writing Trigger Functions in C
39.4. A Complete Trigger Example

This chapter provides general information about writing trigger functions. Trigger functions can be written in most of the available procedural languages, including PL/pgSQL (Chapter 43), PL/Tcl (Chapter 44), PL/Perl (Chapter 45), and PL/Python (Chapter 46). After reading this chapter, you should consult the chapter for your favorite procedural language to find out the language-specific details of writing a trigger in it.

It is also possible to write a trigger function in C, although most people find it easier to use one of the procedural languages. It is not currently possible to write a trigger function in the plain SQL function language.