The concept of a database was made possible by the emergence of direct access storage media such as magnetic disks, which became widely available in the mid 1960s; earlier systems relied on sequential storage of data on magnetic tape.
The Oxford English Dictionary cites a 1962 report by the System Development Corporation of California as the first to use the term "data-base" in a specific technical sense. As computers grew in speed and capability, a number of general-purpose database systems emerged; by the mid-1960s a number of such systems had come into commercial use.
However CODASYL databases were complex and required significant training and effort to produce useful applications. IBM also had their own DBMS in 1966, known as Information Management System (IMS).
These were characterized by the use of pointers (often physical disk addresses) to follow relationships from one record to another. The relational model, first proposed in 1970 by Edgar F.
In 1970, he wrote a number of papers that outlined a new approach to database construction that eventually culminated in the groundbreaking A Relational Model of Data for Large Shared Data Banks. In this paper, he described a new system for storing and working with large databases.
Most other DBMS implementations usually called relational are actually SQL DBMSs. In 1970, the University of Michigan began development of the MICRO Information Management System based on D.L.
The system remained in production until 1998. ===Integrated approach=== In the 1970s and 1980s, attempts were made to build database systems with integrated hardware and software.
However, this idea is still pursued for certain applications by some companies like Netezza and Oracle (Exadata). ===Late 1970s, SQL DBMS=== IBM started working on a prototype system loosely based on Codd's concepts as System R in the early 1970s.
In 1971, the Database Task Group delivered their standard, which generally became known as the CODASYL approach, and soon a number of commercial products based on this approach entered the market. The CODASYL approach offered applications the ability to navigate around a linked data set which was formed into a large network.
Both concepts later became known as navigational databases due to the way data was accessed: the term was popularized by Bachman's 1973 Turing Award presentation The Programmer as Navigator.
Beginning in 1973, INGRES delivered its first test products which were generally ready for widespread use in 1979.
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".
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.
Subsequent multi-user versions were tested by customers in 1978 and 1979, by which time a standardized query language – SQL – had been added.
Though Oracle V1 implementations were completed in 1978, it wasn't until Oracle Version 2 when Ellison beat IBM to market in 1979. Stonebraker went on to apply the lessons from INGRES to develop a new database, Postgres, which is now known as PostgreSQL.
Beginning in 1973, INGRES delivered its first test products which were generally ready for widespread use in 1979.
Subsequent multi-user versions were tested by customers in 1978 and 1979, by which time a standardized query language – SQL – had been added.
Though Oracle V1 implementations were completed in 1978, it wasn't until Oracle Version 2 when Ellison beat IBM to market in 1979. Stonebraker went on to apply the lessons from INGRES to develop a new database, Postgres, which is now known as PostgreSQL.
Relational databases became dominant in the 1980s.
The system remained in production until 1998. ===Integrated approach=== In the 1970s and 1980s, attempts were made to build database systems with integrated hardware and software.
Later on, entity–relationship constructs were retrofitted as a data modeling construct for the relational model, and the difference between the two have become irrelevant. ===1980s, on the desktop=== The 1980s ushered in the age of desktop computing.
The data manipulation is done by dBASE instead of by the user, so the user can concentrate on what he is doing, rather than having to mess with the dirty details of opening, reading, and closing files, and managing space allocation." dBASE was one of the top selling software titles in the 1980s and early 1990s. ===1990s, object-oriented=== The 1990s, along with a rise in object-oriented programming, saw a growth in how data in various databases were handled.
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.
By the early 1990s, however, relational systems dominated in all large-scale data processing applications, and they remain dominant: IBM DB2, Oracle, MySQL, and Microsoft SQL Server are the most searched DBMS.
The data manipulation is done by dBASE instead of by the user, so the user can concentrate on what he is doing, rather than having to mess with the dirty details of opening, reading, and closing files, and managing space allocation." dBASE was one of the top selling software titles in the 1980s and early 1990s. ===1990s, object-oriented=== The 1990s, along with a rise in object-oriented programming, saw a growth in how data in various databases were handled.
The system remained in production until 1998. ===Integrated approach=== In the 1970s and 1980s, attempts were made to build database systems with integrated hardware and software.
In the 2000s, non-relational databases became popular, referred to as NoSQL because they use different query languages. ==Terminology and overview== Formally, a "database" refers to a set of related data and the way it is organized.
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