Oracle DBMS Jobs

Hey Guys/Gals,
I have an interesting question and one where I'm not in the position to be able actively test so hence the reason for the post.

Say I have an Oracle job that is scheduled to run every hour and it just so happens that underlying circumstances make that job run longer than an hour.
Since the job is still running, when it's time for the job to run again will Oracle spawn another process so that the same job is running twice or is Oracle smart enough to know that the job is still running and wait for the job to finish to launch it again?

Also, any docs out there to vaidate what Oracle would actually do?

Thanks for the help! :D

the next_time isnt set until the job finshes - so no you wont get 2 jobs, when the job finishes it will add the interval to that

so if you have a job which runs every hour, it runs at 2pm but takes 90 mins, the next run i believe will be 4

Cool,
Thanks Dave!