Editing Object–relational database (section)

== History ==
Object–relational database management systems grew out of research that occurred in the early 1990s. That research extended existing relational database concepts by adding [[object (computer science)|object]] concepts. The researchers aimed to retain a declarative query-language based on [[Predicate logic|predicate calculus]] as a central component of the architecture. Probably the most notable research project, Postgres (UC Berkeley), spawned two products tracing their lineage to that research: [[Illustra]] and [[PostgreSQL]].

In the mid-1990s, early commercial products appeared. These included Illustra<ref name="stonebraker">Stonebraker,. Michael with Moore, Dorothy. ''Object–Relational DBMSs: The Next Great Wave''. Morgan Kaufmann Publishers, 1996. {{ISBN|1-55860-397-2}}.</ref> (Illustra Information Systems, acquired by [[IBM Informix#1980: Early history|Informix Software]], which was in turn acquired by International Business Machines ([[IBM]]), Omniscience (Omniscience Corporation, acquired by [[Oracle Corporation]] and became the original Oracle Lite), and UniSQL (UniSQL, Inc., acquired by [[KCOM Group]]). Ukrainian developer Ruslan Zasukhin, founder of Paradigma Software, Inc., developed and shipped the first version of Valentina database in the mid-1990s as a [[C++]] [[software development kit]] (SDK). By the next decade, PostgreSQL had become a commercially viable database, and is the basis for several current products that maintain its ORDBMS features.

Computer scientists came to refer to these products as "object–relational database management systems" or ORDBMSs.<ref name="term">There was, at the time, a dispute whether the term was coined by [[Michael Stonebraker]] of Illustra or Won Kim of UniSQL.</ref>

Many of the ideas of early object–relational database efforts have largely become incorporated into [[SQL|SQL:1999]] via [[structured type]]s. In fact, any product that adheres to the object-oriented aspects of SQL:1999 could be described as an object–relational database management product. For example, [[IBM Db2]], [[Oracle Database]], and [[Microsoft SQL Server]], make claims to support this technology and do so with varying degrees of success.