Can an event trigger capture DDL events of dropping objects?

Event triggers are global to a particular database and are capable of capturing DDL events occured in the database. Redrock Postgres supports capturing events of dropping objects at the end of a command (corresponding to the ddl_command_end event).

In the example below, we create an event trigger that captures DDL events that occur in the database at the end of a command.

CREATE OR REPLACE FUNCTION ddl_trigger_func()
  RETURNS event_trigger AS $$
DECLARE
  obj record;
BEGIN
  FOR obj IN SELECT * FROM pg_event_trigger_ddl_commands()
  LOOP
    RAISE NOTICE 'ddl command: %',
      pg_ddl_command_deparse(obj.command);
  END LOOP;
END $$ LANGUAGE plpgsql;

CREATE EVENT TRIGGER ddl_event_trigger
    ON ddl_command_end
    EXECUTE PROCEDURE ddl_trigger_func();

CREATE TABLE t_table (id integer, name text);

DROP TABLE t_table;

In the example above, we will find that when the table t_table is dropped, the event trigger captures the corresponding DDL event.