Oracle 10g very slow when generating report using Crystal Reports

Recently we have upgraded our production database from Oracle 9i to Oracle 10g.
After this, our reports response time got to very bad.

After searching google it reveals that Oracle 10g has a bug in ODBC connection.
I tried to update the ODBC:

1. Upgrade ODBC oracle 10g to version 10.2.0.3.0 (12-Dec-2006) --> the speed still SLOW
2. Set parameter_optimizer_ignore_hints=TRUE either from Initialization Parameter or create trigger like this:

create or replace trigger sys.logon_trigger
after logon on application_user.schema
begin
execute immediate
'alter session set "_optimizer_ignore_hints"=TRUE';
end;
/

Application_user is your schema's name.

After creating the trigger my report generated report faster than before.

I got this from here

  ¶ 1:29 AM