Criar gatilho para id de incerment automático e data e hora unix padrão

CREATE SEQUENCE sequence_name
  START WITH 1
  INCREMENT BY 1
  CACHE 20;

CREATE OR REPLACE TRIGGER trigger_name
  BEFORE INSERT ON table_name
  FOR EACH ROW
BEGIN
  SELECT sequence_name.nextval
    INTO :new.fld_id
    FROM dual;
  :new.fld_date := (SYSDATE - date '1970-01-01') * 60 * 60 * 24;
END;