Avantages
Working at Oracle in sales will get you a job anywhere else ! Their acquisition strategy means you get to sell a large range of products to multiple business lines, though more and more, Oracle keeps acquisition's sales people, then strips complementary products away from the current Oracle salespeople, e.g. when Oracle acquired Siebel, the ERP reps had to literally give their entire non-Siebel CRM pipeline to the incoming Siebel reps, nothing back in exchange. Up goes your quota, down goes your list of products and companies to sell to.
Inconvénients
Larry Ellison has basically 'managed contempt' for sales & marketing, read any of the books to understand why he considers Sales & Marketing an unnecessary overhead, and only select engineering divisions the heroes of the company. Oracle is famous for the '2 strikes' HR rule, you can only leave twice, and once one internal recruiter contacts you about a job, another Oracle recruiter can't touch you till you pass on it least it works in your favor for a 'bidding war' between departments. Yes, Oracle is pretty much entirely unilateral. 'If you're not happy here, how soon can we make you leave ?'