IBM Db2

Db2 is a family of data management products, including database servers, developed by IBM. It initially supported the relational model, but was extended to support object–relational features and non-relational structures like JSON and XML. The brand name was originally styled as DB/2, then DB2 until 2017 and finally changed to its present form. Unlike other database vendors, IBM previously produced a platform-specific Db2 product for each of its major operating systems. However, in the 1990s IBM changed track and produced a Db2 common product, designed with a mostly common code base for L-U-W (Linux-Unix-Windows); DB2 for System z and DB2 for IBM i are different. As a result, they use different drivers. DB2 traces its roots back to the beginning of the 1970s when Edgar F. Codd, a researcher working for IBM, described the theory of relational databases, and in June 1970 published the model for data manipulation. In 1974, the IBM San Jose Research center developed a relational DBMS, System R, to implement Codd's concepts. A key development of the System R project was the Structured Query Language (SQL). To apply the relational model, Codd needed a relational-database language he named DSL/Alpha. At the time, IBM didn't believe in the potential of Codd's ideas, leaving the implementation to a group of programmers not under Codd's supervision. This led to an inexact interpretation of Codd's relational model that matched only part of the prescriptions of the theory; the result was Structured English QUEry Language or SEQUEL. When IBM released its first relational-database product, they wanted to have a commercial-quality sublanguage as well, so it overhauled SEQUEL and renamed the revised language Structured Query Language (SQL) to differentiate it from SEQUEL, and also because the acronym "SEQUEL" was a trademark of the UK-based Hawker Siddeley aircraft company. IBM bought Metaphor Computer Systems to utilize their GUI interface and encapsulating SQL platform that had already been in use since the mid-80s.