Chapter 34. Triggers

Table of Contents
34.1. Overview of Trigger Behavior
34.2. Visibility of Data Changes
34.3. Writing Trigger Functions in C
34.4. A Complete 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 37 ), PL/Tcl ( Chapter 38 ), PL/Perl ( Chapter 39 ), and PL/Python ( Chapter 40 ). 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.