The home was a two-bedroom apartment in Chicago's South Shore neighborhood, populated mostly with lower middle class Jews. Ellison remembers his adoptive mother as warm and loving, in contrast to his austere, unsupportive, and often distant adoptive father, a Russian Jew from the Crimea who adopted the name Ellison to honor his point of entry into the USA, Ellis Island, as well as to conceal his Jewish ancestry. Louis was a modest government employee who had made a small fortune in Chicago real estate, only to lose it during the Great Depression.
Ellison was a bright but inattentive student. He left the University of Illinois at Urbana-Champaign at the end of his second year, after not taking his final exams because his adoptive mother had just died. After spending a summer in Northern California where he lived with his friend Chuck Weiss, he attended the University of Chicago for one term, where he first encountered computer designing. At 20 years of age, he moved to northern California permanently.
Ellison was inspired by the paper written by Edgar F. Codd on relational database systems named "A Relational Model of Data for Large Shared Data Banks." He founded Oracle in 1977, putting up a mere $2000 of his own money, under the name Software Development Laboratories (SDL). In 1979, the company was renamed Relational Software Inc., later renamed Oracle after the flagship product Oracle database. He had heard about the IBM System R database, also based on Codd's theories, and wanted Oracle to be compatible with it, but IBM made this impossible by refusing to share System R's code. The initial release of Oracle was Oracle 2; there was no Oracle 1. The release number was intended to imply that all of the bugs had been worked out of an earlier version.
In 1990, Oracle laid off 10% (about 400 people) of its work force because of a mismatch between cash and revenues. This crisis, which almost resulted in Oracle's bankruptcy, came about because of Oracle's "up-front" marketing strategy, in which sales people urged potential customers to buy the largest possible amount of software all at once. The sales people then booked the value of future license sales in the current quarter, thereby increasing their bonuses. This became a problem when the future sales subsequently failed to materialize. Oracle eventually had to restate its earnings twice, and also to settle out of court class action lawsuits arising from its having overstated its earnings. Ellison would later say that Oracle had made "an incredible business mistake."
Although IBM dominated the mainframe relational database market with its DB2 and SQL/DS database products, it delayed entering the market for a relational database on UNIX and Windows operating systems. This left the door open for Sybase, Oracle, and Informix (and eventually Microsoft) to dominate mid-range and microcomputers.
Around this time, Oracle fell behind Sybase. In 1990-1993, Sybase was the fastest growing database company and the database industry's darling vendor, but soon fell victim to its merger mania. Sybase's 1993 merger with Powersoft resulted in a loss of focus on its core database technology. In 1993, Sybase sold the rights to its database software running under the Windows operating system to Microsoft Corporation, which now markets it under the name "SQL Server."
In 1994, Informix Software overtook Sybase and became Oracle's most important rival. The intense war between Informix CEO Phil White and Ellison was front page Silicon Valley news for three years. Ultimately, Oracle defeated Informix in 1997. In the same year, Ellison was made a director of Apple Computer after Steve Jobs came back to the company. Ellison resigned in 2002, saying that he did not have the time to attend necessary formal board meetings. In November 2005, a book detailing the war between Oracle and Informix was published. " The Real Story of Informix Software and Phil White" provides a detailed chronology of the battle of Informix against Oracle, and how Informix Software's CEO Phil White landed in jail because of his obsession to overtake Ellison.
Once Informix and Sybase were defeated, Oracle enjoyed years of industry dominance until the rise of Microsoft's SQL Server in the late 90s and IBM's acquisition of Informix Software in 2001 to complement their DB2 database. Today Oracle's main competition for new database licenses on UNIX, Linux, and Windows operating systems is with IBM's DB2, the open source database MySQL (bought by Sun in 2008), and with Microsoft SQL Server (which only runs on Windows). IBM's DB2 still dominates the mainframe database market.
In 2005, Oracle paid Ellison a $975,000 salary, a $6,500,000 bonus, and other compensation of $955,100.
Forbes listed Ellison's 2005 net worth as $18.4 billion, making him one of the richest people in America, and the ninth richest man in the world. For a short period in 2000, Ellison was the richest man in the world. In 2006, Forbes ranked Ellison as the richest Californian. Ellison also owns large stakes in both Salesforce.com and NetSuite.
Ellison won the 1998 Sydney to Hobart Yacht Race in his yacht "Sayonara". A storm that broke out during the race cost 6 sailors (none from the Sayonara) their lives, an experience that led Ellison to swear off personal participation in ocean racing.
In response to the September 11th terrorist attacks, Ellison offered to donate to the Federal government software that would enable it to build and run a national identification database and issue ID cards. This offer sparked fierce debate in the media.
In 2002, the leadership of the Ellison Medical Foundation stated that it believed Ellison would increase its annual budget from $35 million to $100 million.
The 2004 Forbes list of the charitable donations made by the wealthiest 400 Americans stated that Ellison had donated $151,092,103 in the preceding year, about 1% of his estimated personal wealth.