4.plan_name : 改变SQL plan 名字
5.description : 改变SQL plan描述
语法：
SET SERVEROUTPUT ON
DECLARE
v_text PLS_INTEGER;
v_text := DBMS_SPM.alter_sql_plan_baseline(sql_handle => 'SYS_SQL_xxxxxx',plan_name => 'SYS_SQL_PLAN_xxxxxxxxx',
attribute_name => 'fixed',attribute_value => 'YES');
DBMS_OUTPUT.put_line('Plans Altered: ' || v_text );
END;
/