Mr Ellison's departure marks two generational shifts. He was the last of the original Silicon Valley greats still in office. Mr Jobs died three years ago; Mr Grove, who has been diagnosed with Parkinson's disease, has turned his considerable energy and much of his considerable fortune to revolutionising how medical research is conducted, making it more goal-oriented and demanding more transparency on research. And, of course, Bill Gates of Microsoft has done much the same to the development sector. Others of that founding generation, like Sun Microsystems' legendary CEO Scott McNealy, have quietly abdicated their leading roles, to return to the excitement of their start-up roots. Mr McNealy, a passionate advocate of the power of networks, now runs Wayin, which deals with social media marketing. James Clark, the power behind two radical innovators, Silicon Graphics and Netscape, has re-invented himself as a successful angel investor; he has backed many companies that have since been acquired by big names in the industry. But Mr Ellison was always the exception, the man least likely to give up control. Indeed, some suspect he is not doing so even now - it has not gone unnoticed that his giant salary, which was drawing angry comments from some Oracle shareholders, will no longer need to be disclosed once he stops being CEO and becomes chief technology officer, his new chosen designation. As CTO, he will lead Oracle's efforts to catch up on the cloud computing revolution, which the company failed to predict.
Whether this transition is real - Mr Ellison has designated two people to share the CEO's job - and how well Oracle manages it, if it is real, will be very closely watched. For, the second transition that Mr Ellison's departure indicates is a shift away not just away from the first start-up entrepreneurs, but also towards younger chief executives, who grew up in a period in which the tech industry had become an industry, and not a calling. In Microsoft, Steve Ballmer, has already handed over command to Satya Nadella. Over at Cisco, John Chambers is still CEO, as he has been since 1995. But he too may step down soon. For some, the change cannot come too soon. Perhaps another Oracle CEO, one less attached to its roots, would have foreseen cloud computing better than Mr Ellison.