SQL> alter session set cursor_sharing = force;

Session altered.

SQL> select /* cursor_sharing2 */ level, -level from dual connect by level < 3 order by 1;

     LEVEL     -LEVEL
---------- ----------
         1         -1
         2         -2

SQL> select /* cursor_sharing2 */ level, -level from dual connect by level < 3 order by 2;

     LEVEL     -LEVEL
---------- ----------
         2         -2
         1         -1

SQL> select sql_text,sql_id,plan_hash_value,literal_hash_value from v$sql s where sql_id = '75qbnnd93d3sw';

SQL_TEXT                                                                                                       SQL_ID        PLAN_HASH_VALUE LITERAL_HASH_VALUE
-------------------------------------------------------------------------------------------------------------- ------------- --------------- ------------------
select /* cursor_sharing2 */ level, -level from dual connect by level < :"SYS_B_0" order by :"SYS_B_1"         75qbnnd93d3sw      3764016154         2342552567
select /* cursor_sharing2 */ level, -level from dual connect by level < :"SYS_B_0" order by :"SYS_B_1"         75qbnnd93d3sw      3764016154         2064090006

SQL> select hash_match_failed from v$sql_shared_cursor where sql_id = '75qbnnd93d3sw';

H
-
N
Y

You’re very good at finding entertaining anomalies.

I wonder if this manages to have some side effects relating to the problems that people can see with bind variable mismatch based on varchar() lengths ?

SQL> alter session set cursor_sharing = force;

Session altered.

SQL> select /* cursor_sharing */ 1 from dual;

         1
----------
         1

SQL> select /* cursor_sharing */ null from dual;

N
-


SQL> select /* cursor_sharing */ -1 from dual;

        -1
----------
        -1

SQL> insert /* cursor_sharing */ into y values (1);

1 row created.

SQL> insert /* cursor_sharing */ into y values (-1);

1 row created.

SQL> insert /* cursor_sharing */ into y values (null);

1 row created.

SQL> commit;

Commit complete.

SQL> select sql_text from v$sql where sql_text like '%/* cursor_sharing */%' order by 1;

SQL_TEXT
------------------------------------------------------------
insert /* cursor_sharing */ into y values (-:"SYS_B_0")
insert /* cursor_sharing */ into y values (:"SYS_B_0")
insert /* cursor_sharing */ into y values (null)
select /* cursor_sharing */ -:"SYS_B_0" from dual
select /* cursor_sharing */ :"SYS_B_0" from dual
select /* cursor_sharing */ null from dual

6 rows selected.

No, there isn’t – even in 11.2
For a list of valid hints you can query v$sql_hint in 11g.

I’ll look into that as soon as I can – and see if I can work out why I thought that my statement was true. I’m fairly sure it would have been 11.1.0.6.

In Which version of 11G filter disappears. It is still there for my 11.1.0.6 on windows

SQL> select * from v$version
  2  ;

BANNER
--------------------------------------------------------------------------------
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
PL/SQL Release 11.1.0.6.0 - Production
CORE    11.1.0.6.0      Production
TNS for 32-bit Windows: Version 11.1.0.6.0 - Production
NLSRTL Version 11.1.0.6.0 - Production

SQL> show parameter optimizer_features_enable 

NAME                                 TYPE                             VALUE
------------------------------------ -------------------------------- ----------------------------------
optimizer_features_enable            string                           11.1.0.6

SQL> show parameter cursor_sharing

NAME                                 TYPE                             VALUE
------------------------------------ -------------------------------- ----------------------------------
cursor_sharing                       string                           SIMILAR

SQL> select id from t1 where rownum=1;

        ID
----------
    128734

SQL> @e2

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------
-------------------------------------------------
SQL_ID  cpbxvfq99ntfb, child number 0
-------------------------------------
select id from t1 where rownum=:"SYS_B_0"

Plan hash value: 3836375644

---------------------------------------------------------------------------
| Id  | Operation          | Name | Rows  | Bytes | Cost (%CPU)| Time     |
---------------------------------------------------------------------------
|   0 | SELECT STATEMENT   |      |       |       |     2 (100)|          |
|*  1 |  COUNT STOPKEY     |      |       |       |            |          |
|   2 |   TABLE ACCESS FULL| T1   |     1 |     5 |     2   (0)| 00:00:01 |
---------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   1 - filter(ROWNUM=:SYS_B_0)


19 rows selected.

SQL> select id from t1 where rownum=2;

no rows selected

SQL> @e2

PLAN_TABLE_OUTPUT
--------------------------------------------------------------------------------------------------------
-------------------------------------------------
SQL_ID  cpbxvfq99ntfb, child number 1
-------------------------------------
select id from t1 where rownum=:"SYS_B_0"

Plan hash value: 624922415

----------------------------------------------------------------------------
| Id  | Operation           | Name | Rows  | Bytes | Cost (%CPU)| Time     |
----------------------------------------------------------------------------
|   0 | SELECT STATEMENT    |      |       |       |   765 (100)|          |
|   1 |  COUNT              |      |       |       |            |          |
|*  2 |   FILTER            |      |       |       |            |          |
|   3 |    TABLE ACCESS FULL| T1   |  1000K|  4882K|   765   (2)| 00:00:10 |
----------------------------------------------------------------------------

Predicate Information (identified by operation id):
---------------------------------------------------

   2 - filter(ROWNUM=:SYS_B_0)


20 rows selected.