DBMS History

DBMS Brief History

The first DBMS was introduced in the 1960's. By the mid-1960's there were several basic database systems that were available for commercial use. In 1971, Charles Bachman of CODASYL intoduced the industry standard for the navigational DBMS and soon there was the emergence of DBMS programs based on the "CODASYL Approach". In 1968, IBM also introduced IMS, which was generally the same as that of the earlier navigational DBMSs.

The earliest introductions of DBMS, were classified as either network or hiereachical models. Both of these early models of DBMS fall under the category of navigational DBMS due to the method used to retreive data. Basically, in order to retreive a pursued set of data, the programmer had to go through the data one by one until the desired record was returned.

Hierarchical Model (basic navigational DBMS)

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The difference between network and hierarchical models, was that the network model allowed a record to have multiple parent and child records. On the contrary, the hierarchical model allowed each record to have only one parent record and multiple child records. The only real advantage to the network model was that in allowed for more natural and simple retreival of data from a DBMS. Both forms of DBMS eventually became obsolete, as computers became more capable of performing complex functions and the relational DBMS was introduced in the early 1980s.

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The introduction of the relational DBMS, revolutionized how data is stored and retreived to this day. Invented by E.F. Codd, the basis of the relational model was that every variable within a database is organized under a given property or relation between entities. These properties are pieces of information that the database contains. A query is used or entered into the database in order to retreive some piece of information from the database. The major difference betweeen navigational DBMS and relational DBMS is that with the introduction of the relational DBMS, data retreival became a function that could be performed in a matter of seconds or minutes rather than hours or days

References

Learning Computin History: Database History. (Dec. 5, 2004). Retreived April 6th, 2009 from http://www.comphist.org/computing_history/new_page_9.htm

A brief History of Modern RDBMS IT Management. (2002). Retreived April 6th, 2009 from http://www.mountainman.com.au/software/history/it2.html