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Assignment Cover Sheet
Qualification Module Number and Title
HND in Software Engineering SEC4205/Database Design Development
Student Name & No. Assessor
Chamila Attanayaka
Hand out date Submission Date
Assessment type
Reports 5000 Words
Duration/Length of
Assessment Type
One Month
Weighting of Assessment
Learner declaration
I certify that the work submitted for this assignment is my own and research sources are fully
acknowledged.
Marks Awarded
First assessor
IV marks
Agreed grade
Signature of the assessor Feedback Form Date
International College of Business & Technology
Module/Title: Database Design and Development /Design a Database Management System
for a private construction firm
Student:
Assessor: Chamila Attanayaka
Assignment:
Acknowledgement
In performing this assessment, I had to take help and guidance from some respected persons, who deserve our greatest gratitude. The completion of this assessment gives me much pleasure. I would like to show my gratitude to Ms. Chamila Attanayake for giving me a good guideline for this assessment throughout numerous consultations. I am extremely grateful to her for providing such a nice guidance and support. I would also like to expand my deepest gratitude to all those who have directly and indirectly guided in performing this assessment.
Dhushiyanthie yogamoorthy
HND in Computing and System Development
Student No: 39
Strong features of your work:Areas for improvement:Marks Awarded:
Table of Contents
Acknowledgement......................................................................................................................
Executive summery
This project was undertaken with a soul purpose of improving the organization current system, so that they may have an increased customer base than before. This report would outline all the pros and cons of the said system will be included in the report. Along with the report inclusion of which database designing module that will be used by the development system.
Organizers of hierarchical data in a data modal hierarchical tree structure, there is a segment of parent and child data. This structure implies that a record may be repetition of information, generally in a data segment child. The serial data records, which have a set of join him sensation values. Collect all records intense specific offer together it in record type. These record types are the same of the table in the relational data model, and individual records that are the similar of rows. To make links between these records users type the modal hierarchical parent-child relationship. This is a one-to-many mapping between the types of records. Here is a diagram for hierarchical data model.
NETWORK DATA MODEL
Network data model is looks like one of developed type of hierarchical data model. Because this also have parent and child connection. And also it is developed than hierarchical data model. Also network data model using many too much relationship in data .network data model is also greater than hierarchical data model. Also network data model is like a set. The network data model details of members or specification have categorizes as set. That set can be called as record. Network data model can have one or more records types. And also these have one to many relationships. Beside that it is permitted for use one to one relationship. When we consider about the diagram given below we can understand about the network data model.
RELATIONAL DATA MODEL
Relational data model is one of another data model. All data and relations are organized in a table. Also there are so many different rules for table. A table is a collection of records and each record in a table contains the same fields.
Values Are Atomic.
The Sequence of Columns is Insignificant.
Each Row is Unique.
Column Values Are of the Same Kind.
Each Column Has a Unique Name.
The Sequence of Rows is Insignificant.
The relational data model is more complex than hierarchical and network data models. Also it covers large area by gathering data in to a table. There is a relation between each other records. Here is a relational data model diagram is given below. The all records are connecting with Sales facts table. Now we can see there have some connection of other record directly or indirectly to sales facts table.
OBJECT RELATIONAL DATA MODEL.
This model is another complex and more successful one of than above data models. Also object relational data model add latest object storage abilities to the relational systems at the core of modern information systems. So it is very useful for modern information systems. Because this object relational data model currently included various binary media like as music, video, pictures. Object relational database management system's server can implement complexes analytical and data
processing operations to search and turn things complex and other multimedia. Designers can work with database structures familiar spreadsheets and definition language, while absorbing new possibilities to manage the object easily and with more performance. Here is the example for object relational data models.
OBJECT ORENTED DATA MODEL.
This model developed by using C++, Java and smart talk object oriented programs. A major benefit of this approach is to unite the application and development of the database to the data model smooth and linguistic environment. Because of that there are more results as like as Applications call for less code, use the more natural data modeling, and code bases easier to maintain. Because of this benefits object developers can easily write data bases with modest application without effort. Unlike an RDBMS a complex structure where data must be flattened to fit into tables or joined together from these tables to form the structure in memory, object oriented DBMS have no performance degradation to store or retrieve a web or a hierarchy of interrelated objects. This mapping one-to-one of the objects of the programming language objects to database objects has two advantages over storage approaches: it provides higher performance management of objects, and allows better management of complex relationships between objects. This makes the most suitable object DBMS to support applications such as financial systems portfolio risk analysis, applications of telecommunications services, world wide web document structures, design and manufacturing systems and patient record systems of hospital, which have complex relationships between data.
New data models comparing to older data models easily accessed because of the linkage between the information. The new models are replaced because of following points,
1. Higher Quality
Quality of work will increase with new technology. Higher quality always produce better productivity. A data model helps define the problem, enabling you to consider different approaches and choose the best one. Quality will determine the best output. New data models will always in to the higher quality.
2. Lower Cost
Data modeling catches errors and oversights early, when they are easy to fix. It can build its applications faster and with fewer errors. The models promote clarity of thought and provide the basis for generating much of the needed database and programming code. So when we sort out the errors the cost will reduce as it is. So new data models will reduce the cost.
3. Quicker time to market
You can also build software faster by catching errors early. In addition, a data model can automate some tasks – design tools can take a model as an input and generate the initial database structure, as well as some data access code. Using data models as a guide for writing SQL code. With this method able to develop SQL-based logic 10 times faster. So, marketing will be quicker.
4. Clearer scope
A data model provides a focus for determining scope. It provides something tangible to help business sponsors and developers. New model must triangulate their respective understandings. Models promote consensus among developers, customers and other stakeholders. The resulting software becomes easier to maintain and extend.
TASK 02...................................................................................................................................
Database Technology
Database technology is a computer based record protection system which is used to record, maintain and retrieve data. It is an organized collection of persistent data.
Database Technology Types
The basic types of database technology are DBMS and RDBMS. DBMS stands for Database Management System and RDBMS for Relational Database Management System. DBMS is MS Access, for RDBMS is Oracle and MySQL.
DBMS (Database Management System)
DBMS is system software for creating, managing and implementing the databases. This database will provide users to create, retrieve, update and manage data. For example, DBMS is referred as MS Access. The following paragraph will give a brief idea about the MS Access.
MS Access is a database management system manufactured by Microsoft, which can be used both by individuals as well as by small business organizations or organizations who want to manage small data.
For managing large databases, Microsoft SQL Server can be used. It can be used to create tables, reports, graphs, forms, charts and matrices. Microsoft access does not require complex programming and thus anyone with basic knowledge of databases and query language can make powerful and effective databases.
There are many advantages of MS Access:
- It can be easily installed and applied.
- It can be easily integrated with all the front end applications like .net, java, php etc.
- MS Access can save us money as it is less bulky and provides same functions as most of the database applications.
- It can store approximately 2 GB of data.
- It provides multi-user support. About 10 users in a network can work simultaneously on one database.
- It is easy to import data from MS Access.
There are some disadvantages of MS Access as well:
- MS Access is useful for individuals and medium to small businesses only. If any organization wants to apply this database, then it will have to face limitations in case its data goes beyond 2 GB.
- MS Access stores all data from the database into one single file. All queries, reports, forms come in on single file, limiting the database access speed.
- Only 10 users in a network can use the database concurrently. If there is requirement for more number of people to use the database simultaneously then they cannot do it.
RDBMS (Relational Database Management System)
RDBMS is the basis for SQL, and for all modern database systems like MS SQL Server, IBM DB2, Oracle, and MySQL. A Relational database management system (RDBMS) is a database management system (DBMS) that is based on the relational model as introduced by E. F. Codd. The following paragraph will give an idea about the systems for RDBMS.
Oracle
Oracle is a database management system manufactured by SUN Microsystems. One of the major advantage as well as disadvantage of oracle is that it is useful only for large organizations with complex database requirements.
Thus advantages of Oracle are:
- Oracle supports large databases.
- It performs each transaction separately and the resultant is not visible to other transaction until it is complete, which makes database secure.
- It makes use of triggers and cursors making programming easy.
- Can handle databases of any size and number of records.
Disadvantage of Oracle:
- Only useful for managing large applications cannot be used with small organizations.
- Price and hardware cost required to run it are very high.
SQL
Microsoft Structured Programming Language or SQL is most widely used query language with lot many advantages:
- It is widely used for managing relational databases
- It is interactive, easy to learn and understand
- It is portable and can run on any kind of device like, pc, laptops, mainframes and mobile phones.
- It is reliable and has robust security mechanism
Figure 1 : Top down Approach
BOTTOM UP APPROACH.................................................................................................
This approach is reverse of top down approach, in a way that it starts from specific and moves towards generic idea. The system analyst, works upon the interface, checking all screens, reports and forms and then moves downwards to check what should be stored in the database. First the interface is created and then database is developed accordingly. An example of this approach can be doctors or physicians, who diagnose the specific symptoms, then infer the general disease causing those symptoms.
Figure SEQ Figure * ARABIC 2 : Bottom up approach
CENTRALIZED APPROACH............................................................................................
DECENTRALIZED APPROACH.......................................................................................
This approach makes use of complex database structure and number of variables. It is mostly practiced in large organizations. This is also useful when the system requirement or problem is spread over many operational sites. To handle this situation, a team of database system engineers have to work on design requirements, constraints, views, validations, interface, various departments etc. Different teams work on different subsets or modules in close coordination, then their work is integrated together to achieve the system objective.
Figure 4 : Decentralized Approach..........................................................................................
TASK 04...................................................................................................................................
ER Diagram
