postgresql 触发器或用户创建存储功能

Question

I am not able to find user creation, password changed, userid updated or last login details in postgresql and for the same I want to create trigger or functions so that it will store database user creation time and when a database user was logged in, along with the password updated time. I want to implement this at database level and not on table level.

I am using below function:

CREATE FUNCTION public.trigger_update_created_and_modified_date()
RETURNS trigger
LANGUAGE 'plpgsql'
COST 100
VOLATILE NOT LEAKPROOF
AS $BODY$

BEGIN
IF (TG_OP = 'INSERT') THEN
EXECUTE format(E'update "%s" set date_created = \'%s\', date_modified = \'%s\'
WHERE id = %s', TG_TABLE_NAME,CURRENT_TIMESTAMP,CURRENT_TIMESTAMP,NEW.id);
ELSEIF (TG_OP = 'UPDATE') THEN
EXECUTE format(E'update "%s" set date_modified = \'%s\'
WHERE id = %s', TG_TABLE_NAME,CURRENT_TIMESTAMP,NEW.id);
END IF;
RETURN NEW;
END

$BODY$;

Is there any other way?

Answer 1

DML triggers only fire on INSERT , UPDATE or DELETE statements, so they cannot be used.

But there are event triggers that fire on CREATE , ALTER or DROP statements. Unfortunately for you, the event trigger firing matrix shows that you cannot have event triggers on CREATE/ALTER/DROP ROLE , so there is no way to get what you want.

What you can get, and what I recommend you do, is to use the log file. Set

log_statement = 'ddl'
log_connections = on

and you will get these events logged.

You can use the csvlog format if you want to parse and digest these log files in an automated fashion.