Query re-write in Desktop and Plus

Question

Under Discoverer Desktop, I am getting very good performance for a particular workbook -- Oracle automatically re-writes the query to go after materialized view, rather than after an original huge table.
But, when I run the exact the same workbook under Discoverer Plus, the query re-write does not happen, and the execution plan is totally different.
When I extract the query from the workbook and run it directly against database via SQL*Plus, the query re-write does happen and performance is excellent.
I am using:
OracleBI Discoverer 10g (9.0.4.00.00)
Oracle Business Intelligence Discoverer Plus 10g (10.1.2.48.18)
Discoverer Model - 10.1.2.48.18
Discoverer Server - 10.1.2.48.18
End User Layer - 5.1.1.0.0.0
End User Layer Library - 10.1.2.48.18
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - 64bi
Are there any Discoverer’s settings that can prevent query re-write under Discoverer Plus?
Thanks.

Answer 1

Do you think this might be related to OracleAS?
This is my current hypothesis, I don't see any other explaination at the moment.
"Discoverer uses its own rewrite system when any of the following is true:
1. The database version is less than 8.1.6
2. The database version is later than 8.1.6 and it is not possible for
Discoverer to create Materialized Views.
The point #2 is applicable to my case.
Marcos, could you please point me to the source of this quotation?
My query is below:
SQL> explain plan for
  2  SELECT O100096.LOCAL_DAY,
  3         O100088.NETWORK_ABBREVIATION,
  4         MAX(O102377.IMPRESSIONS_LIVE)
  5  FROM DOMRSCH.DW_NETWORK           O100088,
  6       DOMRSCH.DW_TIME              O100096,
  7       DOMRSCH.TELECAST_DEMO_RATING O102377
  8  WHERE ((O100096.TIME_KEY = O102377.TIME_KEY) AND
  9        (O100088.NETWORK_KEY = O102377.NETWORK_KEY)) AND
10        (O100096.LOCAL_DAY IN (TO_DATE('20060515000000', 'YYYYMMDDHH24MISS'),
11         TO_DATE('20060516000000', 'YYYYMMDDHH24MISS'),
12         TO_DATE('20060522000000', 'YYYYMMDDHH24MISS')))
13  GROUP BY O100096.LOCAL_DAY,
14           O100088.NETWORK_ABBREVIATION
15  ORDER BY MAX(O102377.IMPRESSIONS_LIVE) DESC;
Explained.
SQL>
SQL> select * from table(dbms_xplan.display);
Plan hash value: 2592166193
| Id  | Operation                     | Name                    | Rows  | Bytes | Cost (%CPU)| Time     |
|   0 | SELECT STATEMENT              |                         |    23 |   414 |     8  (13)| 00:00:01 |
|   1 |  SORT ORDER BY                |                         |    23 |   414 |     8  (13)| 00:00:01 |
|*  2 |   MAT_VIEW REWRITE ACCESS FULL| TELECAST_DEMO_RATING_MW |    23 |   414 |     7   (0)| 00:00