Problem with subqueries returning TIMESTAMP's

Question

I've got problems with some subqueries returning TIMESTAMP values.
I've build a case for easy reproduction, with this query:
SELECT iil.iil_lot_num ,
     (SELECT max ( lot_data_validade )
     FROM lot
     WHERE lot.lot_mat_cod = iil.iil_mat_cod AND
           lot.lot_num = iil.iil_lot_num ) as validade
FROM iil
WHERE ( iil.iil_inv_serie = 109 ) and
      ( iil. iil_inv_num = 16 ) and
      ( iil.iil_mat_cod = 111 )
When I run it, it gives the error:
General error;-9999 POS(1) System error: invalid_indexorder
knldiag also gives:
2009-07-28 15:03:18  9943 ERR 51080 SYSERROR -9999 invalid_indexorder
I'm running on 7.6.06.03.
Previous versions were giving another message:
SQLCODE:  -9999      System error: Otherwise unknown errorcode
If I change max ( lot_data_validade ) to  max ( year (lot_data_validade) ), it works. The problem is specifically with fetching that timestamp value from the subquery.
Backup for reproduction of the problem is on:
http://www.tecnova.com.br/maxdb/backup_problem
(i've isolated only the tables involved in the problem, so the backup is tiny -> 4.3MB)

Answer 1

HI Elke,
I had the same idea at first but was largely disappointed to find that this 'corrupt index' is indeed a temp. resultset:
--> max() query
OWNER         TABLENAME           COLUMN_OR_INDEX     STRATEGY                                  PAGECOUNT
DBA           IIL                                     RANGE CONDITION FOR KEY                           61
                                  IIL_INV_SERIE            (USED KEY COLUMN)                             
                                  IIL_INV_NUM              (USED KEY COLUMN)                             
                                  IIL_MAT_COD              (USED KEY COLUMN)                             
INTERNAL      TEMPORARY RESULT                        EQUAL CONDITION FOR KEY                            1
                                  IIL_INV_SERIE            (USED KEY COLUMN)                             
DBA           LOT                                     NO STRATEGY NOW (ONLY AT EXECUTION TIME)           
INTERNAL      TEMPORARY RESULT                        TABLE SCAN                                         1
                                                           RESULT IS COPIED   , COSTVALUE IS       > 2 E10
The cost expectation is really awesome here...
--> max(year()) query
OWNER     TABLENAME         COLUMN_OR_INDEX  STRATEGY                                  PAGECOUNT
DBA       IIL                                RANGE CONDITION FOR KEY                           61
                            IIL_INV_SERIE         (USED KEY COLUMN)                   
                            IIL_INV_NUM           (USED KEY COLUMN)                   
                            IIL_MAT_COD           (USED KEY COLUMN)                   
INTERNAL  TEMPORARY RESULT                   EQUAL CONDITION FOR KEY                            1
                            IIL_INV_SERIE         (USED KEY COLUMN)                   
DBA       LOT                                NO STRATEGY NOW (ONLY AT EXECUTION TIME) 
                                                  RESULT IS COPIED   , COSTVALUE IS   
This time the optimizer ran out of words for the expected effort for this query execution...
The problem really seems to be the subquery-select as we can strip down the example to
select (select max(lot_data_validade) maxval
from lot
where lot.lot_mat_cod=111) as maxval
from dual
and still see the error...
regards,
Lars