How to get the trigger(s) associated with a view or a table in PostgreSQL

Finding trigger-beasts hiding in your Tables

To start your trigger-hunting journey in PostgreSQL:

• Use system catalogs as your guidebook, information_schema.triggers in particular.
• These catalogs hold the keys to the kingdom. They contain data about your triggers, their table associations, and many other precious database internals.

SELECT 
  event_object_schema AS schema_name,
  event_object_table AS table_name,
  trigger_name
FROM information_schema.triggers;


To close-in on specific targets, simply apply a filter on event_object_table.

The path to trigger enlightenment

Brace yourself for deeper revelations!

This ain't no ordinary catalogue

For a detailed trigger inspection, turn your eyes to PostgreSQL's pg_class, pg_trigger, and pg_namespace. These system catalogs hold the low-level details, offering a well of wisdom about your trigger functions and events:

SELECT 
  t.tgname AS trigger_name, <!-- That's the person...oops...trigger of interest -->
  n.nspname AS schema_name,
  c.relname AS table_name,
  t.tgenabled AS trigger_status, <!-- Is our trigger awake or sleeping? -->
  pg_get_triggerdef(t.oid) AS trigger_definition
FROM pg_trigger t
JOIN pg_class c ON c.oid = t.tgrelid
JOIN pg_namespace n ON n.oid = c.relnamespace
WHERE c.relname = 'your_table_name';


Trigger statuses decoded

The tgenabled column—part of pg_trigger—can tell you if a trigger is active or disabled. Its values ('O', 'D', 'R') represent always firing, disabled, and replica-only respectively. Here's a joke for you: What do triggers and vampires have in common? Both have an 'always firing' mode!

Admin-Preferred trigger sleuthing techniques

Built-in commands: Your toolbelt

psql is like your Swiss Army Knife for PostgreSQL. It provides quick and easy commands for trigger hunting. \dS <table_name> shows triggers for a specific table/view, while \df and \dft list all functions and triggers respectively. Quick and efficient, just like a ninja!

Protecting your kingdom: Trigger management in production

In a production server, triggers are the invisible heroes (or villains) impacting performance. Knowing when and what your trigger does is crucial. Peek into their secret plans with pg_get_functiondef(). It reveals the trigger function and exposes any custom logic.

Troubleshooting: Every admin's bread and butter

If the previous resources don't quench your thirst for knowledge, consulting the wisdom in community discussions (like Stack Overflow) and PostgreSQL's official support becomes your secret weapon. They provide advanced advice tailor-made for your complex needs.