The assignment has been accomplished in order to fulfil the requirements of a small organisation, so that they can maintain their all activities accurately and easily. As a database designer and to find out a suitable database for the organisation, the study describes different types of Database Management System (DBMS) such as RDBMS, ORDBMS and OODBMS. All the positive and negative approaches have been described for each database management system. The description of positive and negative approaches gives the overall idea of using different DBMS. The discussions of DBMS assist to make the perfect selection of database for the organisation. Eventually according to the organisations requirement a suitable DBMS has been proposed.
Introduction: A database is a well prepared collection of data that are connected in a significant way which can be entered in various logical orders but are stored only one time.
DBMS: - A deposit of computer programs that organize the use of database, creation, maintenance, is called Database Management System (DBMS). It permits organizations to put direction of database enlargement in the hand of database administrators (DBAs). A Database Management System is packaging software that helps the exercise of incorporated gathering of data records and files well-known as databases. It permits application for various user programs to simply right of entry the same database. DBMSs use different types of database models, such as the relational model or network model. In bulky systems, a DBMS permits users and other software to accumulate and recover data in a structured way. Thus, many DBMS packages offer Fourth-generation programming language (4GLs) and other application development features. It assists to state the consistent organization for a database and right to use the information within a database. It offers facilities for maintaining access of data, put into effect data integrity, concurrency control, and restoring the database from backups. A DBMS offers the facility to logically present information of database to users. [1]
Database Management Systems have been used for quite a while. Software packages like dBase; Clipper, etc had facilities for managing data. The user had to take care of two aspects - specify what data was to be retrieved and how to go and get the data. [2]
ORDBMS (Object Relational Database Management System):
ORDBMS: - This model has been proposed and is presently being implemented by the Oracle Corporation. This model addresses the shortcomings of the RDBMS model. The Object Relational Database Management System is not purely object oriented. However, it is implemented via the same relational engine that drives the Relational Database Management System. Data is stored in tables. A table is the combination of columns and rows. Each column contains a certain type of data about a person. For example, the first column contains the last name, the second column contains the first name and the third column contains the address. Each row contains all types of data about a person. [3]
Performance Constraints: According to performance ORDBMS transforms data among RDBMS format and object oriented format, speed act of the database is humiliated substantially.
Object data among object database format and a RDBMS format is provided.
It is not essential for programmers to write down code to convert among the two formats and database admittance is simple from an Object Oriented computer language. [3]
Unclear if the ORDBMS will actually combine relationships and encapsulated objects to correctly and completely mirror the 'real world
Provision of a language(s)which will front end to SQL and will provide a migration path for existing SQL users [4]
Relational Database Management System (RDBMS)
RDBMS: - The Relational Model is based on the principles of relational algebra. This model also known as the Relational Database Management System is very popular and is in use by a majority of the Fortune 500 companies. Some of these vendors are: Oracle, SQL Server, Sybase, Informix, Ingress, Gupta SQL, DB2, and Microsoft Access.
The relational database model is stands on the structure of a database. A database is simply a collection of one or more relations or tables with columns and rows. The use of set theory allows for data to be structured in a series of tables that has both columns and rows. Each column corresponds to an attribute of that relation, while each row corresponds to a record that contains data values for an entity.
Benefits:
The main elements of RDBMS are based on the policies for a relational system, the conceptual relational integrity, and normalization. The first fundamental of relational database is that all information will be held in the table form, where every data is described utilizing data values. The second fundamental is that each value found in the table columns does not repeat. The final fundamental is the use of Standard Query Language (SQL).
Benefits of RDBMS are that the system is simple, flexible, and productive. Because the tables are straightforward, data is easier to comprehend and correspond with others. RDBMS is flexible because of users do not need to utilize keys those are predefined to information input. Also, RDBMS are more productive because SQL is easier to learn. This allows users to spend more time inputting instead of learning. More importantly, the advantage of RDBMS is the simplicity with which users are able to create and access data and extend it if needed. After the original database is created, new data categories can be added without the existing application being changed.
Limitations:
There are some drawbacks to the RDBMS (Relational Database Management System). Firstly, relational databases have no enough storage area to handle data (i.e. pictures, audio,video). The system was originally created to handle the integration of media, traditional fielded data, and templates.
Relational databases other drawbacks is its insufficiency to control with languages outside of SQL. After its unique development, languages such as C++ and JavaScript were formed. However, efficiency of relational databases do not work with these languages. Another drawbacks is the requirement of information must be in tables where relationships are defined by values between entities.
Today, the relational model is the dominant data model as well as the foundation for the leading DBMS products, which include IBM's DB2 family, Informix, Oracle, Sybase, Microsoft's Access and SQLServer, as well as FoxBase and Paradox. RDBMS represent close to a multibillion-dollar industry alone. [5]
Semantic overloading.
Poor representation of 'real world' entities
Poor support for integrity & business constraints.
Homogeneous data structure.
Limited operations.
Difficulty handling recursive queries.
Difficulty with 'Long Transactions'.
Normalisation (Normal Forms and FDs) sometimes lead to relations which do not exist, or correspond, to entities in the real world. This compounds on the 'join' feature of query processing
The many to many relationship is difficult to express.
The RDBMS has domains, keys, multi-valued and join dependencies [4]
OODBMS (Object Oriented Database Management System)
Object-Oriented Database Management Systems (OODBMS) are concerned with providing reliable, data independent, protected, controlled and extensible data management services to maintain the object-oriented (OOM) model. They have been created to maintain huge and complex data.
Object-oriented database technology is a bond of object oriented programming (OOP) and database technologies. The following figure illustrates programming and database concepts
Introduction to RDBMS OODBMS and
ORDBMS
Benefits:
The following are the important characteristics of object-oriented database management systems:
Generally the important characteristic is the joining database technology with object-oriented programming.
Providing combined application system development. [5]
Inheritances: Using inheritance complex problems are developed incrementally by defining fresh objects.
Data encapsulation: Internal state of the objects can be hiding by using simple encapsulation or Data encapsulation. There are three types of encapsulated objects:
Full encapsulation: In this encapsulation all operations lying on objects are accomplished by sending of messages and execution of methods.
Write encapsulation: In which only reading operations make the state of object visible.
Partial encapsulation: In which reading and writing of internal state are directly accessed. [5]
Object identity: Each other independent database objects are allowed by object identity.
Polymorphism: Polymorphism allows one to characterize operations for single object and then to distribute the specification of the process with other objects. It also allows users and programmers to create objects to supply solutions without having to write down code that is precise to every object.
DDML (Data Definition and Manipulation Language) is the significant language to OODBMS. This language is used to create, update, delete, or retrieve persistent data. By using DDML users are able to describe a database (involving creating tables, dropping, tables of altering and establishing constraints.
Object-oriented is a further natural approach of thinking.
Operations that are defined not dependent on the particular database application that is running on the system.
Data types can be extended to maintain difficult data in object-oriented database.
Explicit relationships are represented in OODBMS
Users are approved to classify their own methods of access to data. [6]
To supply an integrated application development system object-oriented database technology combines object-oriented programming with database technology. There are many advantages of operations with data definition. These are the following:
Defined operations do not depend on the particular database application.
To maintain complex data (such as defining new multi-media object classes) the data types can be extensive.
a huge number of diverse data types,
a great number of relationships among the objects, and
Objects with difficult behaviours.
Limitations:
Lacks of common data model.
Development stages is still considered without current standard.
Lack of a universal data model
Ad-hoc querying compromises encapsulation.
Locking at object-level impacts performance
Complexity
Lack of support for views
Lack of support for security [4]
Proposed suitable DBMS for the organisation:
According to the above description of the positives and negatives sides of various types of DBMS (Database Management System) I have decided to select ORDBMS as a suitable DBMS. I have selected this DBMS because of ORDBMS allows organisations to carry on using their existing systems, without making major changes. It permits clients and programmers to begin with object-oriented systems in parallel. It is designed to handle huge amounts of information. It is also ensures huge capacity of storage, speed of quick access, massive scalability, outstanding manipulation of power, support rich data.
In ORDBMS, type of system for extensible user, encapsulation, Dynamic binding of methods, complex objects utilizing first normal form are also supported by ORDBMS.
I have emphasized the importance of assessing ORDBMS their capabilities of supporting OOPL. We have first qualitatively considered ORDBMS. Indirectly, these measurements are supposed to contribute to promoting the optimal utilization of currently available ORDBMS in object-oriented system development and to guide the future development. This, on one hand, reduces the implementation efforts, and, on the other hand, increases the entire system efficiency.
As a result, on the basis of current market, ORDBMS is the likely solution by any means. In order to participate in the prospect and also for existence there is no substitute with the use of ORDBMS. So I strongly suggest ORBDMS as the best DBMS (Database Management System) for organisational make use of.
Conclusion:
DBMS have highly developed into the Internet and Web Page. Stocked data is extensively being accessed throughout a Web browser. Today, queries are being executed through Web accessible forms and responds are being arranged using a mark-up language (for example: HTML).
Object Relational database (ORDBMS) is common today as the third type of database. This is the system that "tries to expand relational database systems with the functionality essential to maintain a large class of applications."
In summary, Each Database management System has definite strengths as well as definite weaknesses. In general, the weakness of single type of system is liable to be strength of the other.
For that reason I suppose the ORDBMS will be the most suitable and proper selection for the organisation. The above argument also maintains the decision with any question. So the organisation should take immediate steps to make the ORDBMS system available for their organisational activity and near future.
