Although Bruce Scott is widely considered an Oracle co-founder, technically he wasn't. He was its first hired employee -- or, if you count the founders, employee No. 4. He was the co-architect of the first three versions of the Oracle database.
Scott was with Oracle its first five years and left in 1982 to help launch Gupta Technologies with another ex-Oracle employee, Umang Gupta. (It was later known as Centura Software). The company created the first client/server SQL database and flew high for a while but eventually filed for bankruptcy, and its tech was sold to investors.
Scott landed on his feet, co-founding another database company, PointBase which was acquired by DataMirror, a company that would later be acquired by IBM. Ironically, PointBase is still being used in Oracle's WebLogic software.
Scott took on a number of other engineering roles in the Valley since then and in 2012 co-founded a startup called Cedarcone, a tool to help salespeople.