DBSQL 10-1 Copyright © Genetic Computer School 2009 Chapter 10 Object-Oriented Based DBMS

DBSQL 10-2 Copyright © Genetic Computer School, Singapore 2009 Chapter 10 Overview Object-Oriented DBMS Overview of OODBMS Object-Oriented components and concepts The object-oriented database system policy Comparison of OODBMSs and RDBMSs Object Relational DBMS Object Relational Model Advantages and Disadvantages of ORDBMS Object-Oriented versus Object Relational

DBSQL 10-3 Copyright © Genetic Computer School, Singapore 2009 Object-Oriented DBMS The increase emphasis on process integration is the driving force of object-oriented DBMS application. Examples Advanced office automation systems use object-oriented database systems to handle hypermedia data. Hospital patient care tracking systems use object-oriented database technologies for ease of use All of these applications are characterized by having to manage complex, highly interrelated information, which is strength of object-oriented database systems.

DBSQL 10-4 Copyright © Genetic Computer School, Singapore 2009 Areas where OODBMS Computer Aided Design Computer Aided Manufacturing Computer Aided Software Engineering applications

DBSQL 10-5 Copyright © Genetic Computer School, Singapore 2009 Evolution of OODBMS

DBSQL 10-6 Copyright © Genetic Computer School, Singapore 2009 Object-Oriented Database

DBSQL 10-7 Copyright © Genetic Computer School, Singapore 2009 Characteristics of OO databases It combine OO programming with data OO database technology to integrate various system development applications. Applications of an OODBMS Object identification Object state definition Object relationships identification Object behaviour identification Object classification

DBSQL 10-8 Copyright © Genetic Computer School, Singapore 2009 Object-Oriented components and concepts OODBMS combines the following: Many of the features of the OO programming model Traditional DBMS facilities

DBSQL 10-9 Copyright © Genetic Computer School, Singapore 2009 Comparison of OODBMS and RDBMS OO database systems have been relatively slow to be adopted Relational data models and systems have been very successful for the development of databases used by traditional business applications OO techniques are sometimes favoured in database applications because the OO model is semantically much richer than the earlier data models, thus a database based on the OO model is more capable of storing data the accurately reflects ‘ real world’ information

DBSQL Copyright © Genetic Computer School, Singapore 2009 Problems with OO model OO database is that database are usually not designed to solve specific problems OO technology and its use of encapsulation can often limit its flexibility OO databases is that a large proportion of organizations do not currently deal with the complex data types for which OO technology is ideally suited, and therefore they do not require complex data processing

DBSQL Copyright © Genetic Computer School, Singapore 2009 Object-Relational DBMS Is good for storing and retrieving complex data because it supports complex data types and relationships, multimedia data, inheritance, etc. The object-relational technology, that is, relational technology extended with new capabilities, such as triggers, methods, user defined types, etc., presents two advantages compared with object databases

DBSQL Copyright © Genetic Computer School, Singapore 2009 Object-Relational Model It aims to address some of the problems of pure OO technology such as the poor support for ad hoc query languages, and open database technology, and provide better support for existing relational products, by extending the relational model to incorporate the key features of object-orientation. A major addition to the relational model is the introduction of a stronger type system to enable the use of complex data types, which still allow the relational model to be preserved

DBSQL Copyright © Genetic Computer School, Singapore 2009 Advantages of ORDBMS Resolves many of known weaknesses of RDBMS Reuse and sharing Preserves significant body of knowledge and experience gone into developing relational applications

DBSQL Copyright © Genetic Computer School, Singapore 2009 Disadvantages of ORDMBS Complexity Increased costs Proponents of relational approach believe simplicity and purity of relational model are lost Some believe RDBMS is being extended for what will be a minority of application OO purists not attracted by extensions either. SQL now extremely complex.

DBSQL Copyright © Genetic Computer School, Singapore 2009 OODBMS vs. ORDBMS Differences in: Data Access Data Sharing Data Modelling

DBSQL Copyright © Genetic Computer School, Singapore 2009 End