We are in the process of selecting a database which will need to meet strict industry compliance, have good name recognition, and allow scalability (initially write around 100 ~5k transactions/sec., and respond with large record sets primarily at scheduled intervals, but it could very quickly grow beyond this).
We are being advised to look at Greenplum, and a couple of other paid solutions, but having no experience in this area I would be very interested in hearing at what point you guys have seen it necessary to do this.
Also, when it comes to international customers, and providing a distributed cloud-based solution, are there any databases that are not compatible?