function fId(sCode in varchar2) return integer  as
    nRet C_USR.ID%TYPE;
  begin
    select ID into nRet from C_USR where CODE = sCode;
    return nRet;
  exception
    when NO_DATA_FOUND then
      return null;
  end;

SQL_ID  5x3hrqrr4pnvx, child number 0
-------------------------------------
SELECT ID FROM C_USR WHERE CODE = :B1
 
Plan hash value: 163455779
 
----------------------------------------------------
| Id  | Operation                   | Name         |
----------------------------------------------------
|   0 | SELECT STATEMENT            |              |
|   1 |  TABLE ACCESS BY INDEX ROWID| C_USR        |
|*  2 |   INDEX UNIQUE SCAN         | AK_C_USR_ISP |
----------------------------------------------------
 
Predicate Information (identified by operation id):
---------------------------------------------------
 
   2 - access("CODE"=:B1)
 
Note
-----
   - rule based optimizer used (consider using cbo)
 

Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
PL/SQL Release 11.2.0.4.0 - Production
"CORE	11.2.0.4.0	Production"
TNS for Solaris: Version 11.2.0.4.0 - Production
NLSRTL Version 11.2.0.4.0 - Production

Так исторически сложилось

cursor_sharing= EXACT

select regexp_replace(sql_text,'(\d+)|(''.*?'')','*') str ,count(1)
from v$sqlarea t 
group by regexp_replace(sql_text,'(\d+)|(''.*?'')','*')
having count(1)>10
order by count(1) desc

SELECT /*+ OPT_PARAM('_fix_control' '9088510:0') NO_XML_QUERY_REWRITE cursor_sharing_exact */ count(*)  FROM SYS.DUAL WHERE 1=1

SELECT /*+ OPT_PARAM('_fix_control' '9088510:0') NO_XML_QUERY_REWRITE cursor_sharing_exact */ count(*)  FROM SYS.DUAL WHERE 1 = 1