Not to dwelve too far into Oracle hagiography but,

>During the 1970s, after a brief stint at Amdahl Corporation, Ellison began working for Ampex Corporation. His projects included a database for the CIA, which he named "Oracle". Ellison was inspired by a paper written by Edgar F. Codd on relational database systems called "A Relational Model of Data for Large Shared Data Banks".[10] In 1977, he founded Software Development Laboratories (SDL) with two partners and an investment of $2,000; $1,200 of the money was his.

It's really not clear from the first few hits off Google what his role was in developing Oracle, the application, but he's not like, _untechnical_.

Someone I spoke to after the Sun merger said one of the adjustments Sun engineers had to make was Ellison wandering around desks in Oracle talking about what people were working on, and asking "That looks cool. What could you achieve if I gave another $x million in funding?" if the technology looked interesting to him.

A received anecdote, but the thrust was that Ellison is pretty keenly interested in how it all works, as well as being a ruthless businessman.

Why do you think that a CTO has to be highly technical? Does a CTO at a big technology company write code? Line level engineering managers don't even write code a lot of the time. You just deal in the high-level abstract.