Hello hello hello,
See here what we were waiting for, the new OBIEE 11g.

Q. What if your Dad loses his car keys?
A. ‘Parent keys not found!’
Q. What if your old girl friend spots you with your new one?
A. ‘Duplicate value on index!’
Q. What if the golf ball doesn’t get into the hole at all?
A. ‘Value larger than specified precision!’
Q. What if you try to have fun with somebody [...]

In most case NOLOGGING generetaes no redo; true. But by adding a foreign key constraint to the table it disables direct mode inserts and resorts to conventional mode logging.
The direct load is also disabled for index organized table.

Managemnet and data collection activity can be suspended by imposing a blackout. See here some examples:
agentctl start blackout # Blackout the entrire agent
agentctl stop blackout # Resume monitoring and management
agentctl start blackout ORCL # Blackout DB ORCL
agentctl stop blackout ORCL # Resume monitoring DB ORCL
agentctl start blackout -s jobs -d 00:20 # Blackout jobs for 20 min

If you want to get rid of the content of USER_TAB_MODIFICATIONS or DBA_TAB_MODIFICATIONS then you have to execute dbms_stats.FLUSH_DATABASE_MONITORING_INFO
If that is taking a very long time then you might have hit the oracle bug 5709414

If you want to know if OWB has a future (yes there is competition from ODI/sunopsis); click here.

For people having an Oracle DB on their Laptop runing Windows. See here a cmd to stop and start the services. So if you boot (and put the service on manuel) it will take less resources of your laptop. Then just click the shortcut with the following command to activate your DB.
To stop: net stop [...]

Download the demo material of Oracle Open World 2007 here.