I don't know much about Ellison's story. He certainly has had an unusually long and successful career. I think he had a partner but I can't remember his name now.
Did Ellison really have a visionary connection with computer science? (e.g. along the lines of Gates' "put a computer on every desk") It could be true, but almost nobody thinks of him that way. Certainly relational databases have had an enormous impact on computing and society. Did he ever make any technical contributions, the way Gates and Jobs did? (note: I'm not getting into an argument about Jobs' tech chops :) )
The core technology originated with IBM, and I think IBM had just as much of a role in commercializing it as Oracle, but I don't know much beyond that.
I think there is a meme that Oracle was more of a ruthless competitor, skilled in acquiring other successful companies whose names we don't remember anymore. But perhaps they didn't really move things forward on a technological level the way that Apple and yes even Microsoft did.
https://www.quora.com/Was-Larry-Ellison-a-good-programmer
tl;dr - yes Ellison is/was a pretty good programmer, enjoyed programming, and could handle serious technical discussions. But there seems to be consensus that the guys real genius was in business. Sounds kind of like Gates in that respect, moreso than Jobs, who I believe was never that strong of a coder.