好问题，但是为什么不直接使用log（log_statement = ddl）功能呢？

(postgres@[local]) [sbtest] 16:08:37# CREATE OR REPLACE FUNCTION aaa()
sbtest-#  RETURNS event_trigger
sbtest-#  LANGUAGE plpgsql
sbtest-# AS $$
sbtest$# DECLARE r RECORD;
sbtest$# BEGIN
sbtest$#     FOR r IN SELECT * FROM pg_event_trigger_ddl_commands()
sbtest$#     LOOP
sbtest$#         RAISE NOTICE 'END: command_tag=% type=% identity=% objid=% objsubid=% schema_name=%',
sbtest$#             r.command_tag, r.object_type, r.object_identity, r.objid, r.objsubid, r.schema_name;
sbtest$#     END LOOP;
sbtest$# END; $$;
CREATE FUNCTION
Time: 3.346 ms
(postgres@[local]) [sbtest] 16:08:43# CREATE EVENT TRIGGER bbb ON ddl_command_end
sbtest-#   EXECUTE PROCEDURE aaa();
CREATE EVENT TRIGGER
Time: 2.968 ms
(postgres@[local]) [sbtest] 16:08:48# CREATE TABLE ccc (id int);
NOTICE:  END: command_tag=CREATE TABLE type=table identity=public.ccc objid=25138 objsubid=0 schema_name=public
CREATE TABLE
Time: 7.784 ms
(postgres@[local]) [sbtest] 16:09:23#