Trigger de Logon Oracle

gistfile1.sql

CREATE OR REPLACE TRIGGER "LOGON_ON"
 AFTER
  LOGON
 ON SCHEMA
BEGIN
  EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_DATE_FORMAT="MM/DD/YYYY"';
  EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_NUMERIC_CHARACTERS=".,"';
  EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_TIMESTAMP_FORMAT="MM/DD/YYYY HH24:MI:SSXFF"';
  EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_TIMESTAMP_TZ_FORMAT="MM/DD/YYYY HH24:MI:SSXFF TZR"';
END;