Thanks for the reference. Not being familiar with that topic either, I only set nls_sort. The note shows that I also needed to set nls_comp. Then my previous example shows the same behaviour as William describes:
ora101.scott> ALTER SESSION SET NLS_COMP=ANSI;
Session altered.
ora101.scott> ALTER SESSION SET NLS_SORT=GENERIC_BASELETTER;
Session altered.
ora101.scott> explain plan for select random from m1 where id='000000000550';
Explained.
ora101.scott> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
----------------------------------------------------------------------------------------
Plan hash value: 3061007841
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 100 | 2600 | 287 (5)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| M1 | 100 | 2600 | 287 (5)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(NLSSORT("ID",'nls_sort=''GENERIC_BASELETTER''')=HEXTORAW('
1212121212121212121717120012121212121212121217171200') )
14 rows selected.
PS. As to Mark's suggestion of creating an index on the two columns
in the query to enable an index-only access path. It doesn't work
either because of the nls_sort issue:
ora101.scott> create unique index m1_i2 on m1(id,random);
Index created.
ora101.scott> explain plan for select random from m1 where id='000000000550';
Explained.
ora101.scott> select * from table(dbms_xplan.display);
PLAN_TABLE_OUTPUT
------------------------------------------------------------------------------
Plan hash value: 3061007841
--------------------------------------------------------------------------
| Id | Operation | Name | Rows | Bytes | Cost (%CPU)| Time |
--------------------------------------------------------------------------
| 0 | SELECT STATEMENT | | 100 | 2600 | 287 (5)| 00:00:01 |
|* 1 | TABLE ACCESS FULL| M1 | 100 | 2600 | 287 (5)| 00:00:01 |
--------------------------------------------------------------------------
Predicate Information (identified by operation id):
---------------------------------------------------
1 - filter(NLSSORT("ID",'nls_sort=''GENERIC_BASELETTER''')=HEXTORAW('
1212121212121212121717120012121212121212121217171200') )
I certainly learned something new today.
At 10:20 PM 12/21/2006, Allen, Brandon wrote:
Not familiar with the issue myself until now, but Metalink Note 109118.1 seems to cover it pretty well.Regards, Brandon ----------From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of Jared StillCan you perhaps point out just which documentation you found this in?Privileged/Confidential Information may be contained in this message or attachments hereto. Please advise immediately if you or your employer do not consent to Internet email for messages of this kind. Opinions, conclusions and other information in this message that do not relate to the official business of this company shall be understood as neither given nor endorsed by it.
Regards Wolfgang Breitling Centrex Consulting Corporation www.centrexcc.com
