tailieunhanh - 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. | COP 4710: Database Systems Spring 2004 Introduction to SQL BÀI 13, 2 ngày School of Electrical Engineering and Computer Science University of Central Florida Instructor : Mark Llewellyn markl@ CC1 211, 823-2790 Phd, MS, Under History of SQL SQL, pronounced “S-Q-L” by some and “sequel” by others (mostly old-timers), has become the de facto standard language for creating and querying relational databases. It has been accepted by ANSI (American National Standards Institute) and ISO (International Standards Organization) as well as being a FIPS (Federal Information Processing Standard). Between 1974 and 1979, workers at the IBM Research Laboratory in San Jose, California undertook the development of System R. This was shortly after Codd’s classic paper defining the relational database was published. The goal of the System R project was to demonstrate the feasibility of implementing the relational model in a DBMS. They used a language | COP 4710: Database Systems Spring 2004 Introduction to SQL BÀI 13, 2 ngày School of Electrical Engineering and Computer Science University of Central Florida Instructor : Mark Llewellyn markl@ CC1 211, 823-2790 Phd, MS, Under History of SQL SQL, pronounced “S-Q-L” by some and “sequel” by others (mostly old-timers), has become the de facto standard language for creating and querying relational databases. It has been accepted by ANSI (American National Standards Institute) and ISO (International Standards Organization) as well as being a FIPS (Federal Information Processing Standard). Between 1974 and 1979, workers at the IBM Research Laboratory in San Jose, California undertook the development of System R. This was shortly after Codd’s classic paper defining the relational database was published. The goal of the System R project was to demonstrate the feasibility of implementing the relational model in a DBMS. They used a language named SEQUEL (Structured English QUEry Language), which was a descendent of SQUARE (Specifying QUeries As Relational Expressions), both of which were developed at IBM, San Jose. SEQUEL was renamed to SQL during this project. History of SQL (cont.) 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 versions through these .