Ventajas
Oracle has the most outstanding talent that I've worked with. It is a pleasure to work with such smart and passionate employees. Oracle management has tremendous focus on running a tight business. Given the size of the company, there are plenty opportunities for employees to move around into different roles and learn new technologies and roles. Oracle management at all levels is very open to telecommuting and working remotely, and in general supportive of family needs; of course, it should be noted that it depends a lot on your relationship with your manager. One could easily spend one's entire career working at Oracle, in different roles, and not get bored here.
Desventajas
Oracle is full of type-A personalities. These employees feel passionate, competitive and cut-throat towards their work. As with any large organization, there's always ambiguity about processes such as employee promotions; this can also be read as the management is extremely opportunistic. Oracle operates like a start-up at every level. Driven employees are working extremely hard making it possible to lose sight of life outside Oracle. Again, given the size of the company, there are chances that you might meet a manager that does not exactly see eye to eye with you. Given that there are no explicit guidelines and training for first level managers, individual experience may vary.