"Your database is not commingled with other customers' data," Ellison added. "It's a big difference between our cloud and others on the market." Customers also get their own virtual machine, "so you are protected," Ellison said. "Modern virtual technology is how we offer safety."

Ellison has criticized the practice of multitenancy, a software architecture common in cloud services where a number of customers share a single application instance.

Multitenancy has long been cited as an advantage for cloud companies, since they can upgrade many customers at once, lowering costs, but Ellison turned that argument on its head.

"We think a modern cloud lets you decide when you want to upgrade, not have the cloud vendor tell you when you have to upgrade," he said. "We think that's a very big deal. We'll allow you, within reason, to decide when to upgrade." Customers will get about a one-year window to determine when an available upgrade is right for them, Ellison said.

Some customers may have questions about how often upgrades to Fusion Applications will actually be available, given that Oracle had been criticized for years over the delays in delivering the initial suite. But on Wednesday, Ellison portrayed the project's timeline as something necessary and vital.