Part 1 of Essay
The construction of started in the middle 80's, at a prototype building level, and at the beginning of the 90's the first commercial systems appeared. The interest for the development of such systems stems from the need to cover the modeling deficiencies of their predecessors, that is the relational database management s ....

Part 2 of Essay
.... different data models can be big and substantial. Second is the common theoretical framework. Although there is no standard object-oriented model, most object-oriented database systems that are operational or under development today share a set of fundamental object-oriented concepts. Therefore the implementation issues in OODBMSs that arise due to these concepts are universal. The third characteristic is that of experimental activity. Plenty of prototypes have been implemented and some of them became commercial p ....