title: Trigger data changed of replicated table - postgres
body: <p>I have 2 DB , 1st is master db and 2nd is replica db (just some tables of master DB). I try to add the trigger on replica table to catching when it is replicated from master db tables.</p>
  
  <p>I using the trigger for catching insert, delete and update action but it seem not work. that trigger only work for some table that change from sql statement. Not work for replica tables.</p>
  
  <p>Is there any way to catching the replica tables changes? I using go lang and follow guide of this post 
  <code>https://coussej.github.io/2015/09/15/Listening-to-generic-JSON-notifications-from-PostgreSQL-in-Go/</code></p>
  
  <p>i did these step :</p>
  
  <pre><code>-- create function
  CREATE OR REPLACE FUNCTION notify_event() RETURNS TRIGGER AS $$
  DECLARE
  data json;
  notification json;
  BEGIN
  IF (TG_OP = 'DELETE') THEN
  data = row_to_json(OLD);
  ELSE
  data = row_to_json(NEW);
  END IF;
  notification = json_build_object(
  'table',TG_TABLE_NAME,
  'action', TG_OP,
  'data', data);
  PERFORM pg_notify('events',notification::text);
  RETURN NULL;
  END;
  $$ LANGUAGE plpgsql;
  
  -- create trigger
  CREATE TRIGGER user_warehouse_notify_event
  AFTER INSERT OR UPDATE OR DELETE ON users_warehouse_rel
  FOR EACH ROW EXECUTE PROCEDURE notify_event();
  
  -- enable replica trigger 
  ALTER TABLE users_warehouse_rel ENABLE REPLICA TRIGGER user_warehouse_notify_event
  </code></pre>
  
  <p>it's still not work </p>