Editing Database (section)

===Late 1970s, SQL DBMS===
IBM formed a team led by Codd that started working on a prototype system, ''[[IBM System R|System R]]'' despite opposition from others at the company.{{r|rdbmsearlyyearsoh20070612}} The first version was ready in 1974/5, and work then started on multi-table systems in which the data could be split so that all of the data for a record (some of which is optional) did not have to be stored in a single large "chunk". Subsequent multi-user versions were tested by customers in 1978 and 1979, by which time a standardized [[query language]] – SQL{{Citation needed|reason=First version of SQL standard was SQL-86 adopted in 1986|date=May 2012}} – had been added. Codd's ideas were establishing themselves as both workable and superior to CODASYL, pushing IBM to develop a true production version of System R, known as ''SQL/DS'', and, later, ''Database 2'' ([[IBM Db2]]).

[[Larry Ellison]]'s Oracle Database (or more simply, [[Oracle Database|Oracle]]) started from a different chain, based on IBM's papers on System R. Though Oracle V1 implementations were completed in 1978, it was not until Oracle Version 2 when Ellison beat IBM to market in 1979.<ref>{{cite web|url=https://www.oracle.com/us/corporate/profit/p27anniv-timeline-151918.pdf |archive-url=https://web.archive.org/web/20110320220813/http://www.oracle.com/us/corporate/profit/p27anniv-timeline-151918.pdf |archive-date=2011-03-20 |url-status=live |title=Oracle 30th Anniversary Timeline |access-date=23 August 2017}}</ref>

Stonebraker went on to apply the lessons from INGRES to develop a new database, Postgres, which is now known as [[PostgreSQL]]. PostgreSQL is often used for global mission-critical applications (the .org and .info domain name registries use it as their primary [[data store]], as do many large companies and financial institutions).

In Sweden, Codd's paper was also read and [[Mimer SQL]] was developed in the mid-1970s at [[Uppsala University]]. In 1984, this project was consolidated into an independent enterprise.

Another data model, the [[entity–relationship model]], emerged in 1976 and gained popularity for [[database design]] as it emphasized a more familiar description than the earlier relational model. Later on, entity–relationship constructs were retrofitted as a [[data modeling]] construct for the relational model, and the difference between the two has become irrelevant.{{Citation needed|date=March 2013}}