Poor performance on Discoverer after upgrade to 11g database

Question

Hello,
We have two customers who have experienced a sharp decline in the time it takes to run their queries when they have upgraded to an 11g database.
One was a full Disco upgrade from 4 to 10 plus the database upgrade.
The other was purely a database upgrade - Discoverer version was already 10g.
They were both on 9i database.
They are both Oracle Apps - and the reports are based on a mixture of everything from standard tables to custom tables - there is no pattern (or one that we have seen) in the poorly performing reports.
I have not seen much on metalink regarding this - has anyone else come across why this would be?
It does seem to be only Discoverer - standard reports and the app are performing as expected.
Any advice welcome,
Thanks
Rachael

Answer 1

Hi Rachael
There are additional database privileges needed for running in 10g and 11g databases that weren't needed in 9i. Here's the typical privileges that I use:
accept username prompt'Enter Username: '
accept pword prompt'Enter Password: '
create user &username identified by &pword;
grant connect, resource to &username;
grant analyze any to &username;
grant create procedure, create sequence to &username;
grant create session, create table, create view to &username;
grant execute any procedure to &username;
grant global query rewrite to &username;
grant create any materialized view to &username;
grant drop any materialized view to &username;
grant alter any materialized view to &username;
grant select any table, unlimited tablespace to &username;
grant execute on sys.dbms_job to &username;
grant select on sys.v_$parameter to &username;
I appreciate that all of the above are not needed for all users and some are only needed if the user is going to be scheduling.
However, I do know that sys.v_$parameter was not needed in 9i. Can you check whether you have this assigned?
I know this might sound silly too, but you need to refresh your database statistics in order for Discoverer to work well. You might also want to try turning off the query predictor if it is still enabled.
Best wishes
Michael