What is an Object-Oriented Database Management System?

Object-oriented database management system (OODBMS) is a database management system that supports the simulation and creation of data as objects. The object-oriented data model is the foundation of the object-oriented database structure. The key to the design of the object-oriented database management system is its new data model object, namely the object-oriented data model, and the transformation of the data model into the database structure.

Object-oriented database management system (OODBMS) is a database management system that supports the simulation and creation of data as objects. It includes support for object classes and support for subclasses and their objects' inheritance of class attributes and methods. At present, what constitutes OODBMS standards has not been widely recognized, and OODBMS products are considered to be in their infancy. In the meantime, an object-related database management system (ORDBMS) has the concept that the concept of an object-oriented database can be added to a relational database. This concept is more common in available products. The object-oriented database interface standard was developed by the industry group and became the Object Data Management Group (ODMG).

In the Object-Oriented Database Statement, Malcolm Atkinson and other authors define OODBMS as follows:

An object-oriented database system must meet two criteria: it must be a database management system, and it must be an object-oriented system, for example, it must be compatible with the current object-oriented programming language to the extent possible. The first standard translates into five characteristics: persistence, secondary storage management, synchronization, defensiveness, and a specific inquiry tool. The second standard translates into eight characteristics: complex objects, object consistency, encapsulation, types, inheritance, late constraints, extensibility, and computational completeness.

The development of the database management system must go through two stages of requirements analysis and system design. When the requirements analysis is completed and the design phase is entered, the database design is usually performed. The quality of the database design is directly related to the later development of the system. The traditional requirement analysis uses data flow diagrams, and the database design uses the entity-relation model method (ER method). It is difficult for the requirements analyst and the database designer to agree on the application understanding. If an object-oriented analysis method is used in the requirements analysis phase, and an object-oriented design method is used in the database design, the object model in the requirements analysis phase can be naturally transformed into a database structure.

For a database system to become an object-oriented database system, it must have the characteristics of the object-oriented system and its database, support the core object-oriented data model, and expand and modify the semantics of the traditional database to make it consistent with the core object-oriented data model. . The object-oriented data model is the foundation of the object-oriented database structure. The key to the design of the object-oriented database management system is its new data model object, namely the object-oriented data model, and the transformation of the data model into the database structure. ^[1]

Objects, classes, and inheritance form the basis of the structural characteristics of the object-oriented data model.They have the following meanings:

(1) Object is the most basic unit of data structure and operation.

(2) Each object has a unique, identifiable value provided by the system

A database system based on object-oriented technology is composed of several objects and the interaction between these objects. Among them, objects are composed of data and operations. Objects are autonomous, encapsulated and dynamic. The application of object-oriented technology to each stage of software engineering is to find the object and the interaction between the objects. In the requirements analysis stage, object-oriented analysis is to model real-world objects. The fundamental starting point is to describe and describe the problem domain from the perspective of application, which is conducive to understanding the problem. The results of the requirements analysis phase are: problem statement + object model + dynamic model + function model. The design stage is a further description of the original object model. At this stage, an object-oriented method can be used to implement the database design. Object data model in database design based on object-oriented technology and database management system

OOP technology, which can naturally represent complex data models, can improve the uniformity of application systems. Increasingly complex systems are looking forward to an environment that can be constructed in a short period of time with high efficiency. For example, we need to construct a personnel database management system containing image and voice processing in a short period of time. There is no doubt that it is difficult to meet this requirement with traditional system development methods. However, if it is assumed that the basic data system, sound system and image system related to personnel management already exist, then this relatively complex personnel database management system can be simply defined in a window. So the object-oriented database management system attracts people's attention as an indispensable system.

It must be pointed out that an OODBMS is itself an object. And it is composed of several objects with completely independent functions and the coordination relationship between each object. The making process of an OODBMS can be simply described with the following figure.

It can be seen from the figure that the key to the design and implementation of OODBMS lies in the production of objects. In addition to the production of objects, corresponding tools and supporting environments are required. One of the biggest problems is to abstract objects from intricate data relationships and implement them with object-oriented programming language based on the smallest unit of knowledge. Object-oriented programming is not a new concept. However, it is only in the era of multimedia that the data relationship becomes quite complicated, and in the case of short development cycle requirements and many changes in specifications, it has fully shown its charm in the field of processing large amounts of information, and has the development field that dominates the DBMS Propensity. However, a complete development environment including the debugging of the production system needs further study. ^[2]