DROP TRIGGER log_errors_trig;
DROP TABLE   log_errors_tab;
 
CREATE TABLE log_errors_tab (
     error     VARCHAR2(30),
     TIMESTAMP DATE,
     username  VARCHAR2(30),
        osuser    VARCHAR2(30),
        machine   VARCHAR2(64),
     process   VARCHAR2(8),
     program   VARCHAR2(48));
 
CREATE OR REPLACE TRIGGER log_errors_trig 
     after servererror ON database
DECLARE
     var_user     VARCHAR2(30);
     var_osuser   VARCHAR2(30);
     var_machine  VARCHAR2(64);
     var_process  VARCHAR2(8);
     var_program  VARCHAR2(48);
BEGIN
     SELECT username, osuser, machine, process, program
     INTO   var_user, var_osuser, var_machine, var_process, var_program
     FROM   sys.v_$session
     WHERE  audsid = USERENV('sessionid');
 
     INSERT INTO log_errors_tab
       VALUES(dbms_standard.server_error(1),SYSDATE,var_user,
              var_osuser,var_machine,var_process,var_program);
END;