Database Systems - Part 13
System R itself was never produced commercially, but directly led
to the development of SQL/DS (1981 running under DOS/VE OS, a
VM version followed in 1982) which was IBM’s first commercial
relational DBMS.
• IBM however, did not produce the first commercial implementation
of a relational DBMS. That honor went to Oracle (Relational
Software) in 1979.
• Today, the relational DBMS system of virtually all vendors is based
on SQL.
• Each vendor provides all the standard features of SQL. Most
vendors also provide additional features of their own, called
extensions to standard SQL. These extensions lead to portability
issues when moving SQL-based applications across various
RDBMS. Vendors attempt to distinguish their SQL...
