system r

if you are interested in where todays databases are based on you might interested in the following link:

A History and Evaluation of System R

for example these requirements ( taken from the link above ) have been defined back in the 1970ies and are still valied today:

1. To provide a high-level, nonnavigational user interface for maximum user productivity and data independence
2. To support different types of database use including programmed transactions, ad hoc queries, and report genereration
3. To support a rapidly changing database environment, in which tables, indexes, views, transactions, and other objects could easily be added to and removed from the database without stopping the system.
4. To support a population of many concurrent users, with mechanisms to protext the integrity of the database in a concurrent-update environment
5. To provide a means of recovering the contents of the database to a consistent state after a failure of hardware or software
6. To provide a flexible mechanism whereby diffent views of stored data can be defined and various users can be authorized to query and update these views
7. To support all of the above functions with a level of performance comparable to exsiting lower-function database systems.