I think first of all you need to figure out why your queries are taking longer than 100 seconds. Unless your running a migration script, your queries should be much faster.

Is this the query you were trying to run, or are you using that as an example? If so, there's absolutely no good reason a simple select query should take that long.

Changing the timeout period is generally a bad idea, because it allows bad queries to run rampant on your server. It seems to me that there is something very wrong going on with your Oracle database. If you aren't the admin, you should contact whoever is and ask them to look into it.