Oracle lawyers have complained they have been unable to subpoena former SAP executive Leo Apotheker to testify in Oracle's copyright case against SAP.
Apotheker was due to start in a new role as chief executive at Hewlett-Packard when the trial started on Monday, but he is currently out of the country, according to US reports.
SAP and HP say Apotheker is not relevant to the case and that Oracle is harassing him, but Oracle chief Larry Ellison insists there is evidence that Apotheker knew of the wrongdoing by now-defunct SAP subsidiary TomorrowNow while it was going on.
SAP has acknowledged financial responsibility for TomorrowNow illegally accessing Oracle support software to lure away customers, but says Oracle is exaggerating the business impact.
Oracle is seeking damages and licence fees for the software stolen by TomorrowNow of at least $2bn (£1.2bn), while SAP says it should pay only tens of millions of dollars, for the profits Oracle lost as a result of the theft.
The fourth day of the trial in Oakland, California included testimony by former Oracle president Charles Phillips, who said the licensing for the stolen software would have been worth at least $3bn.
While Phillips was giving testimony, SAP attorney Greg Lanier showed the court e-mails between Phillips and other Oracle executives that suggested Oracle did not see TomorrowNow as a big threat.
Lanier argued that the e-mails showed that customers were leaving Oracle not because of TomorrowNow, but because they were unimpressed with Oracle's software road map.
Ellison is expected to take the stand on Monday.