Database History

Home	Databases have been used in the early days of computers. Many older systems used custom databases for better speed and flexibility. As computers grew, databases became more popular. In the 1960s, there were a number of database products available. Charles Bachman, author of Integreated Data Store (IDS), founded a group called "Database Task Group" within CODASYL from COBOL. In 1971, they developed the "Codasyl approach" and thereafter other commercial products were based on that. The Codasyl approach used a manual navigation of a linked data set to form into a large network. When this database was opened, it went to the first record and this record contained pointers to other data. The programmer had to look through these pointers to find a certain record. Simple queries required the program to walk through the data set and return matching results. IBM had their own Database Management System (DBMS) system in 1968. This was called IMS, which was software written for the Apollo program on the System/360. IMS was similar to Codasyl, but used different data navigation. Both became known as navigational databases. IMS is a hierarchical database. IDS, IDMS, and CINCOMs TOTAL database are network databases.
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In the 1970s, Edgar Codd worked at IBM and did not like that there was no "search" feature in the navigational model of the Codasyl approach. Codd wrote a paper describing a new system. Instead of records being stored in a linked list, a "table" was used of fixed-length records. Eugene Wong and Michael Stonebraker from Berkeley became interested in Codd's paper and started a project, INGRES, and students produced the code.

In 1973, INGRES delivered its first test products that were used widespread in 1979. INGRES used a language called QUEL, which was corrupted to follow the Structured Query Language (SQL).

IBM started developing a system similar to System R, which was a database system in the 1970s. System R was implemented with SQL. This later became SQL/DS and then Database 2 (DB2).

Sybase, Informix, and NonStop SQL were sold in the INGRES product in the 1980s. Microsoft SQL Server is a re-built version of Sybase.

Larry Ellison's Oracle was based on System R and beat IBM in the marketplace with its first release in 1978.

Stonebraker used the concept of INGRES to develop Postgres, a new database now known as PostgreSQL. PostgreSQL is mainly used for global critical applications.

In Sweden, Mimer SQL was developed based on Codd's paper in the mid-1970s at Uppsala University. In the 1980s, Mimer introduced transaction handling for high robustness in applications and this was implemented on other DBMS.