Object oriented Database design: Characteristics and Advantages
Characteristics of Object oriented database
- It keeps up a direct relation between real world and database objects as if objects do not loose their integrity and identity.
- OODBs provide system generated object identifier for each object so that an object can easily be identified and operated upon.
- OODBs are extensible, which identifies new data types and the operations to be performed on them.
- Provides encapsulation, feature which, the data representation and the methods implementation are hidden from external entities.
- Also provides inheritance properties in which an object inherits the properties of other objects.
Enriched modeling capabilities
The object-oriented data model allows the ‘real world’ to be modeled more closely. The object, which encapsulates both state and behavior, is a more natural and realistic representation of real-world objects. An object can store all the relationships it has with other objects, including many-to-many relationships, and objects can be formed into complex objects that the traditional data models cannot cope with easily.
OODBMSs allow new data types to be built from existing types. The ability to factor out common properties of several classes and form them into a superclass that can be shared with subclasses can greatly reduce redundancy within system is regarded as one of the main advantages of object orientation. Further, the reusability of classes promotes faster development and easier maintenance of the database and its applications.
Capable of handling a large variety of data types
Unlike traditional databases (such as hierarchical, network or relational), the object oriented database are capable of storing different types of data, for example, pictures, voice video, including text, numbers and so on.
Removal of impedance mismatch
A single language interface between the Data Manipulation Language (DML) and the programming language overcomes the impedance mismatch. This eliminates many of the efficiencies that occur in mapping a declarative language such as SQL to an imperative ‘language such as ‘C’. Most OODBMSs provide a DML that is computationally complete compared with SQL, the ‘standard language of RDBMSs.
More expressive query language
Navigational access from the object is the most common form of data access in an OODBMS. This is in contrast to the associative access of SQL (that is, declarative statements with selection based on one or more predicates). Navigational access is more suitable for handling parts explosion, recursive queries, and so on.
Support for schema evolution
The tight coupling between data and applications in an OODBMS makes schema evolution more feasible.
Support for long-duration, transactions
Current relational DBMSs enforce serializability on concurrent transactions to maintain database consistency. OODBMSs use a different protocol to handle the types of long-duration transaction that are common in many advanced database application.
Applicability to advanced database applications
There are many areas where traditional DBMSs have not been particularly successful, such as, Computer-Aided Design (CAD), Computer-Aided Software Engineering (CASE), Office Information System(OIS), and Multimedia Systems. The enriched modeling capabilities of OODBMSs have made them suitable for these applications.
There have been a number of benchmarks that have suggested OODBMSs provide significant performance improvements over relational DBMSs. The results showed an average 30-fold performance improvement for the OODBMS over the RDBMS.