I would suggest that you check the [url]http://technet.oracle.com[/url] or [url]http://metalink.oracle.com[/url] for a shared memory and semaphores. There are some good white papers there which would help you to better undestand the parameter setups. Currently I'm experienceing trouble in connecting to metalink and when I get it I'll try to cut and past that article for you, in case if you don't have the support.

Sam