[DATABASE] History of Databases

History of Databases - From Trees To Objects

The storage and management of data is probably the biggest headache for all businesses.

It has been so for a long while and is likely to continue for a long while too. As companies aim to store more and more details about their customers and their buying habits, they need to store and manage more and more data. The only way this can be done efficiently and at a reasonable cost is by the use of computers.

In the late 1960s/early 1970s, specialised data management software appeared the first database management systems (DBMS). These early DBMS were either hierarchical (tree) or network (CODASYL) databases and were, thererfore, very complex and inflexible which made life difficult when it came to adding new applications or reorganising the data. The solution to this was relational databases which are based on the concept of normalisation - the separation of the logical and physical representation of data.

In 1970 the relational data model was defined by E.F. Codd (see "A Relational Model of Data for Large Shared Data Banks" Comm. ACM. 13 (June 6, 1970), 377-387).

In 1974 IBM started a project called System/R to prove the theory of relational databases. This led to the development of a query language called SEQUEL (Structured English Query Language) later renamed to Structured Query Language (SQL) for legal reasons and now the query language of all databases.

In 1978 a prototype System/R implementation was evaluated at a number of IBM customer sites.

By 1979 the project finished with the conclusion that relational databases were a feasible commercial product.

Meanwhile, IBM's research into relational databases had come to the attention of a group of engineers in California. They were so convinced of the potential that they formed a company called Relational Software, Inc. in 1977 to build such a database. Their product was called Oracle and the first version for VAX/VMS was released in 1979, thereby becoming the first commercial rdbms, beating IBM to market by 2 years.

In the 1980s the company was renamed to Oracle Corporation. Throughout the 1980s, new features were added and performance improved as the price of hardware came down and Oracle became the largest independent rdbms vendor. By 1985 they boasted of having more than 1000 installations.

As relational databases became accepted, companies wanted to expand their use to store images, spreadsheets, etc. which can't be described in 2-dimensional terms. This led to the Oracle database becoming an object-relational hybrid in version 8.0, i.e. a relational database with object extensions, enabling you to have the best of both worlds.

Source : A Short Oracle Tutorials for Beginners