In what appears to be an extended shakeup at the top of Oracle, two senior executives Wednesday announced their departure from the database giant.In what appears to be an extended shakeup at the top of Oracle, two senior executives\u00a0Wednesday announced their departure from the database giant.Mark Jarvis, a 14-year Oracle veteran who headed up marketing as chief marketing officer, and George Roberts, who worked at Oracle for 13 years and was involved in setting up the company's sales model, are leaving Oracle, a company spokeswoman confirmed.The departures were announced in an e-mail Oracle CEO Larry Ellison sent to Oracle personnel, she said.Robert's departure was not unexpected. He had ceded control of North American sales, consulting and application development marketing to Keith Block last year.Chuck Phillips, an Oracle executive vice president who played an important role in launching Oracle's hostile takeover bid for PeopleSoft, will take over control of the marketing department, Ellison said in the e-mail. Phillips was recently recruited to Oracle after years on Wall Street as an analyst covering enterprise software and is one of Ellison's new prot\u00e9g\u00e9s.Jarvis' departure is the latest in a string at the marketing department. Last year Jeremy Burton, senior vice president of product marketing left Oracle for storage software vendor Veritas Software. He was later followed by Rene Bonvanie, a vice president for marketing at Oracle. It is unknown where Jarvis is headed.