About CURSOR_SHARING value in view V$ses_OPTIMIZER_ENV

 Hi,     Database version is 10.2.0.4 .When i query the gV$ses_OPTIMIZER_ENV for cursor_sharing,it is giving strange value.
    
    SQL> show parameter cursor_sharing

NAME                                 TYPE        VALUE
------------------------------------ ----------- ------------------------------
cursor_sharing                       string      EXACT

SQL> select  SID,name,value from gV$ses_OPTIMIZER_ENV  where name like 'cursor%'
  2  ;

       SID NAME                                     VALUE
---------- ---------------------------------------- -------------------------
        15 cursor_sharing                           exact
        16 cursor_sharing                           exact
        18 cursor_sharing                           exact
        19 cursor_sharing                           uninit
        20 cursor_sharing                           uninit
        21 cursor_sharing                           exact
        22 cursor_sharing                           exact
        23 cursor_sharing                           uninit
        24 cursor_sharing                           exact
        25 cursor_sharing                           uninit
        26 cursor_sharing                           exact

       SID NAME                                     VALUE
---------- ---------------------------------------- -------------------------
        27 cursor_sharing                           exact
        28 cursor_sharing                           exact