Why would Oracle, which makes most of its money from databases and business software, buy a hardware firm? A big part of the reason is the outsized appetite of Larry Ellison, Oracle’s flamboyant chief executive. His firm has spent around $30 billion buying 50 firms since 2005, among them software heavyweights such as PeopleSoft, Siebel and BEA. Buying Sun should help Mr Ellison achieve his goal of getting Oracle’s revenues above $30 billion by the end of this year.