SQL) is becoming established as the standard for relational databases. Nearly all database suppliers use the language. ANSI has ratified a version of it.
The article looks at the history of sQL, its current importance, and the problems it currently faces.
SQL, standards, relational databases, relational languages
HISTORY OF SQL
The relational database and SQL stories both start at the same time -in 1970 when Dr Edgar Codd first laid down a set of abstract principles for database management: the so-called relational model. The entire field of relational database technology has its origins in that paper I .
One aspect of Codd's research was the design and implementation of a variety of relational languages. Several such languages were created in the early and mid-1970s. One was SQL, which was developed during IBM's System R project in the mid-1970s. SQL was implemented in two IBM products -SQL/DS for DOS/VSE and VM/CMS, and DB2 for MVS.
Over the next few years, numerous other vendors also announced SQL-based products. There are now over 50 or so products in the marketplace that support some dialect of SQL. SQL has become the de facto standard in the relational database world.
SQL is also a de jura standard. ANSI now recognises a relational database language standard 2, based closely on IBM's version of SQL.
SQL is already established in the mainframe and minicomputer environments. It is increasingly seen as the 'glue' likely to hold together distributed networks of database.
In addition, more and more SQL implementations are being announced for PCs: SQL is, for example, set to become part of the extended edition of the OS/2 operating system; Lotus and IBM have agreed to 61 Foxhollow, Bar Hill, Cambridge CB3 8ES, UK develop jointly a SQL-based PC relational database; and Microsoft and Ashton-Tate are marketing a SQL-based network file server.