PostgreSQL - Campo timestamp sem milissegundos

CREATE OR REPLACE FUNCTION self_destroy() RETURNS void AS
$BODY$
BEGIN
DROP TABLE IF EXISTS mslxp_self_destroy;
CREATE TEMP TABLE mslxp_self_destroy
(
dt1 timestamp    without time zone,
dt2 timestamp(0) without time zone
);
INSERT INTO mslxp_self_destroy(dt1, dt2) VALUES (clock_timestamp(), clock_timestamp());
DROP FUNCTION self_destroy();
END;
$BODY$
LANGUAGE plpgsql;

SELECT self_destroy();
SELECT * FROM self_destroy;

Resultado:
2012-05-18 11:10:03.414 | 2012-05-18 11:10:03

PostgreSQL - Função para usar printf em pgsql

http://wiki.postgresql.org/wiki/Sprintf

# select printf('% is a % and % is a %, but %% is a %', '{hello,word,1,number,percent sign}');
                      printf
------------------------------------------------------------
hello is a word and 1 is a number, but % is a percent sign
(1 fila)

IfThen do Delphi no PostgreSql

CREATE OR REPLACE FUNCTION public.ifthen(cond boolean, iftrue varchar, ifelse varchar) RETURNS varchar AS
$BODY$
BEGIN
    IF cond THEN
        RETURN iftrue;
    ELSE
        RETURN ifelse;
    END IF;
END;
$BODY$ LANGUAGE 'plpgsql';