Query slow in 11g

Question

Hi,
One of my DEV database was recently upgraded to 11.1.0.6. The platform used is HPUX IA64.
One of the procedure is running fine in Oracle 9i ( current production).
The same procedure is hung in Oracle 11g. As per application team, there has been no changes. The same procedure runs with < 100 rows( with rownum < 100 condition ,<1000., <10000 etc). But when we remove the condition, its running for few hours without any result.
Declare               
CURSOR c_all_emps IS
  select persn_id, hier_lvl_no, rptg_hier_lvl
  from jjhrdb.emp_hier_lvl  
  where rownum<10000;
prev_wwid      NUMBER  (9) :=0;
hier_rec_ctr   NUMBER  (9) :=0;
supvr_lvl        integer        ;
c              NUMBER  (9) :=0;
s                NUMBER  (9) :=0;
len            NUMBER  (9) :=0;
x                NUMBER  (9) :=0;
nn                NUMBER  (9) :=0;
persn_id                       integer      ;
hier_lvl_no                       integer      ;
supvr_persn_id                 integer      ;
supvr_wwid                     NUMBER(14)    ;
rptg_hier                        varchar2 (4000);
rptg_hier_lvl                   varchar2 (4000);
Procedure InsertRec ( i_pid in integer, i_spid in integer,
                         i_slvlno in number     )is
Begin
        insert into jjhrdb.emp_hier (persn_id, supvr_lvl_persn_id, supvr_lvl_no)
    values (i_pid,i_spid,i_slvlno);
    exception when others then
         /*insert into ksen.kserror values(    i_spid,' ',err_desc); */
         dbms_output.put_line(i_spid||' '||sqlerrm);
         commit;
End InsertRec;
-- Begin Main Block.
Begin
For c_ae in c_all_emps loop
    hier_rec_ctr := hier_rec_ctr + 1;
    PERSN_ID         := c_ae.persn_id            ;
    Hier_LVL_No         := c_ae.hier_lvl_no            ;
    RPTG_HIER_LVL    := c_ae.RPTG_HIER_LVL        ;
        x := 1;
        while (instr(c_ae.rptg_hier_lvl,',',1,x)) != 0 loop
            len := length( trim(c_ae.rptg_hier_lvl)) ;
            c  := instr(c_ae.rptg_hier_lvl,',',1,x) ;
            s  := instr(c_ae.rptg_hier_lvl,' ',1,x) ;
               if x = 1 then
                    supvr_persn_id := substr(c_ae.rptg_hier_lvl,1,(c -1) );
                else
                    nn := instr(c_ae.rptg_hier_lvl,' ',1,(x-1))+1 ;
         supvr_persn_id := substr(c_ae.rptg_hier_lvl,nn,(c-nn) );
                End if;
                if s != 0 then 
                    supvr_lvl := substr(c_ae.rptg_hier_lvl,(c+1),(s -(c+1)) ) ;
                else
                    supvr_lvl := substr(c_ae.rptg_hier_lvl,(c+1),(len+1) ) ;
                End if;
        /*    SetEmpHier(persn_id, fmly_nm, given_nm);  */
  /* dbms_output.put_line(persn_id||supvr_persn_id|| supvr_lvl); */
            InsertRec(persn_id, supvr_persn_id, supvr_lvl);
            x:=x+1;
        End loop;     /*  while  */
End loop;     /*  for   */
commit;
dbms_output.put_line ('TOTAL EMP HIER: ' || hier_rec_ctr || ', ');
--last record processing:
/*  For c_eh in c_emp_hier loop
        SetEmpHier(persn_id, fmly_nm, given_nm);
        InsertRec(persn_id);
     End loop;       for   */
-- Begin Anon Update Block.
/* xBegin
  xupdate law_hstq
  set jobcd_flsa = (select exmpt_ind from lawrpt.rpt_jobcode
  where jobcode = job_cd);
  commit;
end;    */
End; 
/

Answer 1

Hello,
When you upgrade to 11g some sql statements regress because you are using a different optimizer version.i recommend if you run sql access advisor from the enterprise manager against this sql statement.
Kind regards
Mohamed