Another area is the sheer scale of the task of moving large data sets from data centres to the public cloud providers. Teradata is both a customer and a competitor of Amazon Web Services, offering analytics on the AWS cloud.
Clark explained: "How do you move a petabyte of data to the cloud? You don't. Because a petabyte of data is hard to move to the cloud. You may have seen Amazon Snowball, which has 80 terabytes, and they'll send it out to you. But that wasn't enough so Amazon introduced Snowmobile.
"No one has found a way to overcome physics, not even Amazon. So this is one of the reasons that analytics is one of the last things to move to cloud - because who the heck wants to move this data all over the place?"
Clark said that the best approach to moving to the cloud differs greatly for customers, and private or managed clouds can be more appropriate in some cases.
"One thing we find is that there isn't one answer," he said. "A lot of times people come to me and ask what cloud I should move to, and I say I don't know, maybe you should move to multiple clouds. There are some that don't think that is a good strategy, that you should have just one cloud, but you have one point of failure. They are all at different places in their journey to the cloud."