Research Journal of Recent Sciences ________________________________________________ ISSN 2277-2502
Vol. 1 (ISC-2011), 419-421 (2012)
Res.J.Recent Sci.

Mini Review Paper

Performance Interoperability between RDBs and OODBs
Shukla Brahma Datta and Gupta V.K.
Department of Computer Science, NIMS University, Jaipur, Rajasthan, INDIA
Available online at: www.isca.in
(Received 11th October 2011, revised 27th February 2012, accepted 30th March 2012)

Abstract
Object-oriented databases and relational database are becoming more and more popular for applications to support the complexity
and the irregularity of the real-world entities. Object-Oriented Databases (OODBs) have been designed to support large and
complex programming projects. The data accuracy, consistency, and integrity in OODBs are extremely important for developers
and users. In Object Oriented Data Model each record is represented by object. The basic element of an object-oriented database
is the object. A relational database allows the definition of data structures, storage and retrieval operations and integrity
constraints. In such a model the data and relations between them are organized in tables. A table is a collection of records and
each record in a table contains the same fields. Object-oriented database systems began developing in the mid-80’s out of a
necessity to meet the requirements of applications beyond the data processing applications which were served by relational
database systems. In this paper, the Achievements and weaknesses of both database models and the Special problems found in the
both model are discussed. This paper deals with different constraints in object-oriented databases and relational database.
Keyword: Distributed database system, relational model, objects oriented model, database, security, homogeneous, heterogeneous,
constraint etc.

Introduction
For the last several years the most used database1 model has
been relational. While the relational model has been useful,
its utility is reduced if the data does not fit into a relational
table. Many organizations have data requirements that are
more complex than can be handled with these data types.
Multimedia data, graphics, and photographs are examples of
these complex data types.
As advances in computer-related technology improve,
increasingly larger files can be created, transmitted, and
stored electronically. It thus becomes more apparent that
object-oriented technology, and object-oriented databases in
particular, are needed to warehouse the files or “objects.” In
contrast to the relational database model, an object-oriented
database stores objects, which consist of data as well as
procedures that are used to perform operations on that data.
About 88 percent of organizations use relational databases1,
yet about 55 percent plan to acquire object-oriented
databases at some point in the future. Main discussion of this
paper is object-oriented database and compared with
relational database. In this paper, the strengths and
weaknesses of both database models and the Special
achievements found in the object-oriented database are
discussed.
Relational Database: A relational database management
system (RDBMS)1 is a database management system
(DBMS) that is based on the relational model as introduced

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by E. F. Codd. Most popular databases currently in use are
based on the relational database model. A short definition of
an RDBMS is: a DBMS in which data is stored in tables and
the relationships among the data are also stored in tables. The
data can be accessed or reassembled in many different ways
without having to change the table forms.
A relational database is a set of tables containing data fitted
into predefined categories. Each table (which is sometimes
called a relation) contains one or more data categories in
columns. Each row contains a unique instance of data for the
categories defined by the columns. For example, a typical
business order entry database would include a table that
described a customer with columns for name, address, phone
number, and so forth. Another table would describe an order:
product, customer, date, sales price, and so forth. A user of
the database could obtain a view of the database that fitted
the user's needs. For example, a branch office manager might
like a view or report on all customers that had bought
products after a certain date. A financial services manager in
the same company could, from the same tables, obtain a
report on accounts that needed to be paid.
Object-oriented Databases: The basic element of an objectoriented database2 is the object. A class defines an object. In
essence, classes are the blueprints for objects. In the objectoriented model, classes are arranged in a hierarchy. The root
class is found at the top of the hierarchy. This is the parent
class for all other classes in the model. We say that a class
that is the descendent from a parent inherits the properties of
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Research Journal of Recent Sciences ____________________________________________________________ ISSN 2277-2502
Vol. 1 (ISC-2011), 419-421 (2012)
Res. J. Recent Sci.
the parent class. As needed, these properties can be modified
and extended in the descendent class. An object is composed
of two basic elements: variables and methods.
An object holds three basic variables types: (1) Object class
(2) Object ID (OID) (3) Data Stores.

Figure-1
Object-oriented database
Methods perform two basic functions: They communicate
with other objects and they perform reads and updates on the
data in the object. Methods communicate with other objects
by sending messages. Methods perform all reading and
writing of the data in an object. For this reason, we say that
the data is encapsulated in the object. This is one of the
important differences between object-oriented and relational
databases. All control for access, modification, and integrity
start at the object level. For example, if no method exists for
updating a particular object's variable, then the value of that
variable is constant. Any change in this condition must be
made at the object level.
When database capabilities are combined with objectoriented programming language capabilities, the result is an
object-oriented database management system (OODBMS).
OODBMS2 allow object-oriented programmers to develop
the product, store them as objects, and replicate or modify
existing objects to make new objects within the OODBMS.
Because the database is integrated with the programming
language, the programmer can maintain consistency within
one environment, in that both the OODBMS and the
programming language will use the same model of
representation. Relational DBMS projects, by way of
contrast, maintain a clearer division between the database
model and the application.
The class composition hierarchy is represented by IS-PARTOF relationship, and class inheritance hierarchy is
represented by IS-A relationship. The Object-Oriented Data
Model (OODM) can support three types of relationships
between classes, which are:
Composition hierarchy (logical or physical composition) is a
relationship between two classes where the instances of one

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class are in someway attributes, methods, and constraints of
the other.
Inheritance hierarchy (single or multiple inheritance) is a
relationship between superclasses and subclasses. A
superclass may have any number of subclasses, which
subclasses inherit attributes and methods of superclass. This
means all global attributes, methods, and constraints in a
superclass exist in subclasses. In addition, subclasses may
have additional attributes, methods, and constraints. Class
association is a relationship between classes that can be in
the form of 1:1, 1:M, or M:N. Composite objects are
grouping of inter-related objects that can be viewed logically
as a single object.
Achievements of OODBs over RDBs: OODBs allow
representation of complex objects in a more straightforward
way than relational systems. In this section we will discuss
some of the achievements of OODBs so far: OODBs allow
users to define abstractions, facilitate the development of
some relationships, eliminate the need for user defined keys,
have developed a new set of equality predicates, eliminate
the need for joins in some cases, have performance gains
over the RDB model in some situations, and have support for
versioning and long duration transactions. Finally, object
algebra has been developed, although it may not be as
developed as relational algebra yet.
OODBs allow users to define abstractions: OODBs have the
ability to define new abstractions and to control the
implementation of these abstractions.
OODBs facilitate development of some relationships:
OODBs offer the feature of inverse relationships to express a
mutual reference between two objects (a binary relationship).
OODBs eliminate need for user-defined keys: The OODB
model has an OID that it is automatically generated by the
system and that guarantees uniqueness to each object.
OODBs reduce need for Joins: OODBs have the ability to
reduce the need of join.
Performance gain using OODBs: Most current OODBs are
not full-fledged database systems comparable to current
RDBs, OODBs have a few sources of performance gain over
RDBs:
Support for versioning or long-duration transactions:
Versioning and long-duration transactions are missing in
RDBs. Few OODBs offer versioning and long-duration
transactions, though with limited facilities only.
Development of Object Algebra: Though not as developed
and mature as relational algebra, object algebra has been
developed that defines five fundamental object-preserving
operators: union, difference, select, generate and map.

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Research Journal of Recent Sciences ____________________________________________________________ ISSN 2277-2502
Vol. 1 (ISC-2011), 419-421 (2012)
Res. J. Recent Sci.
Weaknesses of OODBs: The expectation was that objectoriented technology would bring a quantum jump to database
technology. But, in spite of the achievements of OODBs
discussed above, OODBs have not been able to make a major
impact because of weaknesses still present in OODB model
and technology.
In OODBs there is a lack of basic features that users of
database systems have become accustomed to, and therefore
expect. The features include, lack of interoperability between
RDBs and OODBs, minimal query optimization, lack of
standard query algebra, lack of query facilities, no support
for views, security concerns, no support for dynamic class
definition changes, limited support for consistency
constraints, limited performance tuning capabilities, little
support for complex objects, limited integration with existing
object-oriented programming systems, limited performance
gains, among others.

provide one or more of the following: a query language;
indexing; transaction support with rollback and commit; the
possibility of distributing objects transparently over many
servers. These features are described. Main part of this paper
is comparison of object-oriented database with relational
database. An object-oriented database is an entirely different
beast from a relational database.
For future work, I plan to examine security level in object
oriented Database System. We are in the process of
investigating schemes by which the performance of high
security level transactions can be improved without
compromising with the security. Further we are looking to
secure real time object oriented distributed systems by which
the performance of high security level transactions can be
improved without compromising the security.

References

Need for OODBs: Relational data model has several
restrictions. Object-oriented data model, based on the object
oriented paradigm for programming and data management
gained popularity in last few decades because of the
advantages it provides in supporting complex object and
multi-valued attributes.

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Object-oriented databases support inheritance, objectidentity, encapsulation, rich type system (including
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Extending object-oriented languages to support database
operations: Object-relational model: extends relational
model and provides rich type system of object-oriented
databases, combined with relations as basis of for storage of
data.
Interoperability between RDBs and OODBs: For OODBs2
to make a major impact on the database market, following
has to be done:
OODBs have to be made full-fledged database systems,
sufficiently compatible with RDBs – a migration path is
needed to allow the coexistence and the gradual migration
from the current products to new products; Application
development tools and database access tools have to be
developed for such database systems; Architectures of the
RDBs and OODBs have to be unified; The data models of
the RDBs and OODBs have to be unified.

Conclusion
We have discussed object oriented database and relational
database. We also discussed various constraints of both
database models. We have seen that Object-Oriented
Databases3 have been designed to support large and complex
programming projects. Object Oriented Databases generally
provide persistent storage for objects. In addition, they may

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System Environment,

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