编译过程导致ORA-4068错误

ORA-04068: existing state OF packages has been discarded.
ORA-04065: NOT executed, altered OR dropped stored PROCEDURE P_PACKAGE.P_PRO
ORA-06508: PL/SQL: could NOT find program unit being called: P_PACKAGE.P_PRO
ORA-06512: at line 1

ORA-04068: existing state of packages has been discarded. ORA-04065: not executed, altered or dropped stored procedure P_PACKAGE.P_PRO ORA-06508: PL/SQL: could not find program unit being called: P_PACKAGE.P_PRO ORA-06512: at line 1

SELECT do.obj# d_obj,do.name d_name, do.type# d_type,
po.obj# p_obj,po.name p_name,
to_char(p_timestamp,'DD-MON-YYYY HH24:MI:SS') "P_Timestamp",
to_char(po.stime ,'DD-MON-YYYY HH24:MI:SS') "STIME",
decode(sign(po.stime-p_timestamp),0,'SAME','*DIFFER*') X
FROM sys.obj$ do, sys.dependency$ d, sys.obj$ po
WHERE P_OBJ#=po.obj#(+)
AND D_OBJ#=do.obj#
AND do.status=1 /*dependent is valid*/
AND po.status=1 /*parent is valid*/
AND po.stime!=p_timestamp /*parent timestamp not match*/
ORDER BY 2,1;

select do.obj# d_obj,do.name d_name, do.type# d_type, po.obj# p_obj,po.name p_name, to_char(p_timestamp,'DD-MON-YYYY HH24:MI:SS') "P_Timestamp", to_char(po.stime ,'DD-MON-YYYY HH24:MI:SS') "STIME", decode(sign(po.stime-p_timestamp),0,'SAME','*DIFFER*') X from sys.obj$ do, sys.dependency$ d, sys.obj$ po where P_OBJ#=po.obj#(+) and D_OBJ#=do.obj# and do.status=1 /*dependent is valid*/ and po.status=1 /*parent is valid*/ and po.stime!=p_timestamp /*parent timestamp not match*/ order by 2,1;