Terms were not disclosed. However, Rick Sherlund, analyst with Nomura Securities, estimated Oracle paid between $750 million and $900 million.
Redwood Shores, Calif.-based Oracle reported cash and investments exceeding $31.5 billion at the end of its first quarter on Aug. 31. CEO Larry Ellison said Oracle intends to remain the world's top database company especially as computing moves to the cloud as well as across bigger enterprises.
The move further bolsters Oracle, the world's leading database developer, in the battle for analyzing unstructured data in battles against rivals including IBM, Hewlett-Packard and Microsoft. HP just acquired Endeca rival Autonomy for about $10.5 billion.
Endeca, based in Cambridge, Mass., was founded in 1999 by Steve Papa, a Princeton graduate with a background in operations research as well as a Harvard MBA.
Since then, its main products, Endeca InFront for e-commerce and Endeca Latitude for business intelligence have been adopted by enterprise users to sift through massive piles of data using its own MDEX Engine database software.
Customers include the U.S. Defense Intelligence Agency, IBM, Boeing, Texas Instruments and Wal-Mart Stores. The software is especially useful searching for unstructured data in media companies as well business.
Papa raised about $75 million in venture capital from Venrock Partners, the Rockefeller family firm, as well as Bessemer Venture Partners, Ampersand Ventures, Intel Capital and DN Capital. Another investor is SAP Ventures, which is controlled by Oracle's German arch-rival SAP.
Earlier this year, Papa estimated annual revenue this year would be about $150 million.
Oracle shares traded around $31.90, up 2 percent, in late trading Tuesday.