1977–1994 During the 1970s, after a brief stint at
Amdahl Corporation, Ellison began working for
Ampex Corporation. His first project included a database for the
CIA, code-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". In 1977, Ellison, Ed Oates and Bruce Scott joined Software Development Laboratories (SDL) several months after it was founded by Ellison's supervisor at Ampex, Bob Miner. They invested $2,000 (), of which $1,200 () was Ellison's. Although he had strong technical skills—Ellison was not officially categorized as a developer until about 1984—the founders decided that as the others were stronger technically, he would run sales. In 1979, the company renamed itself Relational Software, Inc. (RSI). Ellison had heard about the
IBM System R database, also based on Codd's theories, and wanted Oracle to achieve compatibility with it, but IBM made this impossible by refusing to share System R's error codes. The initial release of the
Oracle Database in 1979 was called Oracle version 2; there was no Oracle version 1. In 1983, the company officially became Oracle Systems Corporation (named after its flagship product). In 1990, Oracle laid off 10% of its workforce (about 400 people) because it was losing money. This crisis, which almost resulted in the company'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 those future sales failed to materialize. Oracle eventually had to restate its earnings twice, and had to settle
class-action lawsuits arising from its having overstated its earnings. Ellison later said 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,
Ingres,
Informix, and eventually
Microsoft to dominate mid-range systems and microcomputers. Around this time, Oracle fell behind Sybase. From 1990 to 1993, Sybase was the fastest-growing database company and the database industry's darling vendor. 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". Sybase soon fell victim to
merger mania; its 1996 merger with Powersoft resulted in a loss of focus on its core database technology. In 1990, Ellison was named Entrepreneur of the Year by Harvard University.
1994–2010 In 1994, Informix 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. In April 1997, Informix announced a major revenue shortfall and earnings restatements. White eventually landed in jail. Also in 1997, Ellison was made a director of
Apple Computer after
Steve Jobs returned to the company. Ellison resigned from that position in 2002. With the defeat of Informix and Sybase, Oracle enjoyed industry dominance until the rise of Microsoft SQL Server in the late 1990s and IBM's acquisition of Informix Software in 2001 to complement its
DB2 database. By 2013 Oracle's main competition for new database licenses on UNIX,
Linux, and Windows operating systems came from IBM's DB2 and from Microsoft SQL Server. IBM's DB2 still dominated the
mainframe database market. In 2005, Ellison agreed to settle a four-year-old insider-trading lawsuit by offering to pay $100 million () to charity in Oracle's name. In 2005, Oracle Corporation paid Ellison a $975,000 salary (), a $6,500,000 bonus (), and other compensation of $955,100 (). In 2007, Ellison earned a total compensation of $61,180,524 (), which included a base salary of $1,000,000 (), a cash bonus of $8,369,000 (), and options granted of $50,087,100 (). In 2008, he earned a total compensation of $84,598,700 (), which included a base salary of $1,000,000 (), a cash bonus of $10,779,000 (), no stock grants, and options granted of $71,372,700 (). In the year ending May 31, 2009, he made $56.8 million (). In 2006,
Forbes ranked him as the richest Californian. In April 2009, after a tug-of-war with IBM and
Hewlett-Packard, Oracle announced its intent to buy
Sun Microsystems. In July 2009, for the fourth year in a row, Oracle's board awarded Ellison another 7 million stock options. In August 2009, it was reported that Ellison would be paid only
$1 for his base salary for the fiscal year 2010, down from the $1,000,000 () he was paid in fiscal 2009.
Since 2010 After approval from regulators in the
United States and the
European Union, Oracle acquired its competitor Sun Microsystems on January 21, 2010. The Sun acquisition also gave Oracle control of the popular
MySQL open source database, which Sun had acquired in 2008. In August 2010, Ellison denounced Hewlett-Packard's board for firing CEO
Mark Hurd, writing: "The HP board just made the worst personnel decision since the idiots on the Apple board fired Steve Jobs many years ago." Ellison and Hurd were close personal friends. In September, Oracle hired Hurd as co-president alongside
Safra Catz. Ellison remained in his CEO role. Ellison was an early investor in
Theranos. He is played by
Hart Bochner in the 2022 miniseries
The Dropout, about Theranos and its founder
Elizabeth Holmes. In March 2010, the
Forbes list of billionaires ranked Ellison as the sixth-richest person in the world and as the third-richest American, with an estimated net worth of over $28 billion (). In September 2011, Ellison was listed on the
Forbes list of billionaires as the fifth richest man in the world and was still the third richest American, with a net worth of about $36.5 billion (). In September 2012, Ellison was again listed on the
Forbes list of billionaires as the third richest American citizen with a net worth of $44 billion (). In October 2012, he was listed as the eighth-richest person in the world, according to the Bloomberg Billionaires Index. Ellison owns stakes in
Salesforce.com,
NetSuite,
Quark Biotechnology Inc. and
Astex Pharmaceuticals. In June 2012, Ellison agreed to buy 98 percent of the Hawaiian island of
Lānaʻi from
David H. Murdock's company,
Castle & Cooke. The price was reported to be between $500 million () and $600 million (). In 2013, according to
The Wall Street Journal, Ellison earned $94.6 million (). On September 18, 2014, Ellison appointed
Mark Hurd to CEO of Oracle from his former position as president;
Safra Catz was also made CEO, moving from her former role as CFO. Ellison assumed the positions of chief technology officer and executive chairman. In November 2016, Oracle bought NetSuite for $9.3 billion (). Ellison owned 35% of NetSuite at the time of the purchase making him $3.5 billion personally (). In 2017,
Forbes estimated that Ellison was the 4th-richest person in the technology sector. In June 2018, Ellison's net worth was about $54.5 billion (), according to
Forbes. In December 2018, Ellison became a director on the board of
Tesla, Inc., after purchasing 3 million shares earlier that year. Ellison left the Tesla board in August 2022. In June 2020, Ellison was reported to be the seventh-wealthiest person in the world, with a net worth of $66.8 billion (). In late 2022, Ellison owned 42.9% of the shares of Oracle Corporation, and in June 2023, he owned 1.4% of the shares of Tesla. Ellison's software startup, Project Ronin, which he co-founded with
David Agus and Dave Hodgson, closed in 2024. The company intended to transform cancer care using products intended to quickly analyze data within electronic medical records systems. In August 2025, Ellison provided funding through his family trust for the
merger of Paramount Global with his son David's Skydance Media. The trust remains the largest owner of the new company's shares while David retains operational control. On September 10, 2025, Ellison was briefly the wealthiest person in the world, with an estimated net worth of $393 billion. In 2026, President Trump appointed Ellison to the
President's Council of Advisors on Science and Technology (PCAST). ==Political involvement==