The reason? Part of the answer lies in Siebel's analytics functionality, which the company had only recently begun to roll out when Oracle announced its plans to buy the firm.
Oracle execs have publicly called Siebel's analytical software the "hidden jewel" in the acquisition. Oracle wants to keep pace with other enterprise software firms -- especially Microsoft -- that are tacking more and more analytics abilities onto their tools.
So it's no surprise that Oracle will retain "90 percent" of Siebel's support, development engineers, sales and sales engineers, according to CEO Ellison.
Instead, most of the cuts will come from Oracle's established ranks. Oracle's executive team doesn't want to throw out the people who can turn over Siebel's "hidden jewel."