Using timestamp in function

Hi,

I am using PostgreSQL 7.4 and was trying to log the time each part of a
function needs. I found a pretty helpful bit of code in the documentation:

http://www.postgresql.org/docs/7.4/static/plpgsql-expressions.html

I used the following function, called inside the another function:

CREATE or replace FUNCTION mylog_test(integer, varchar) RETURNS
timestamp AS '
DECLARE
n ALIAS FOR $1;
logtxt ALIAS FOR $2;
curtime timestamp;
BEGIN
curtime := ''now'';
--INSERT INTO logger VALUES ( nextval(''seq_log''), curtime,
substr(logtxt,0,200));
RAISE NOTICE ''TIME: %'',curtime;
RETURN curtime;
END;
' LANGUAGE plpgsql;

I expected, that the variable curtime gets a new time value, each time
the function is called (at least that is what I understood from the
documentation). This works fine, if I test it with
SELECT mylog_test(5, 'test');
But as soon as I call the funtion from another function (which I need)
the variable curtime does not change anymore.

Can anyone tell me why this does not work and does anyone know a
solution to this?

For test purposes here is a function called test, which does nothing
else than to call mylog_test(..) and spend some time calculating.

CREATE or replace FUNCTION test() RETURNS text AS '
DECLARE
i integer;
j integer;
k integer;
BEGIN
FOR i IN 1..10 LOOP
PERFORM mylog(3, ''val '' || i);
FOR j IN 1..2000000 LOOP
k:=j;
END LOOP;
END LOOP;
RETURN ''THE END'';
END;
' LANGUAGE 'plpgsql';

SELECT test();

Any help is appreciated

Silke