The construction of Object-Oriented Database Management Systems started in the middle 80's, at a prototype building level, and at the beginning of the 90's the first commercial The interest for the development of such systems stems from the need tocover the modeling deficiencies of their predecessors, that is the relational databasemanagement systems. They were intended to be used by applications that have to handle bigand complex data such as Computer Aided Engineering, Computer Aided Design, and OfficeInformation Systems. The area of the OODBMSs is characterized by three things. First, it lacks a common datamodel. There is no common data model although many proposals can be found in theliterature. This is a more general problem of all the object-oriented systems not only thedatabase management systems. Since the data model determines the database language ofthe system, which in turn determines the implementation of the system, we can understandthat the differences between the various systems with different data models can be big andsubstantial. Second is the common theoretical framework. Although there is no standardobject-oriented model, most object-oriented database systems that are operational or underdevelopment today share a set of fundamental object-oriented concepts. Therefore theimplementation issues in OODBMSs that arise due to these concepts are universal. The thirdcharacteristic is that of experimental activity. Plenty of prototypes have been implementedand some of them became commercial products. There is really a need for applications tohandle very complex data and that is why the interest of people in building such systems isso strong.Although there is no consensus on what an OODBMS is and which are the features thatdifferentiate it from other systems, there has been a lot of effort for an agreement ondefining the formal characteristics that can stand as the set of specification requirements...
