Analysis of different database design approaches

http://www.programmingassignmentshelp.net/

2016

Analysis of Different Database Design Approaches

Web Design and Development Augustine Barlow

Programming Assignment Help

There are two approaches used for designing any database, the top-down method and the bottom-up method. While these approaches are different, they focus on uniting a system by describing all of the interaction between the processes.

Top – down design method In this method, data sets are identified first and then defines the data elements for each of those sets. This process involves the identification of different entity types and the definition of attributes of each entity.

Bottom - Up design method In this method, data elements are identified first and then they are grouped together in data sets. In other words, it first defines attributes, and then groups them to form entities.

Conceptual Model

Attribute

Entity

Attribute

Attribute

Attribute

p U tm o B

n w D p To

Entity

The selection of a top-down or bottom-up approach depends on the scope of the problem or on personal preferences. A primary emphasis on a bottom-up approach may be more productive for small databases with few entities, attributes, relations, and transactions. For situations where the number, variety, and complexity of entities, relations, and transactions is high, top-down approach may be more easily managed.

Depending on such factors, database design may be Centralized or De-Centralized.

Programing Assignment Help

Page 2

Centralized Design This design is more productive when the data component is composed of small number of objects and procedures. Centralized design is simple and can be successfully done by a single person (database administrator) or by a small, informal design team. A single designer can define the problem(s), create the conceptual design, verify the conceptual design with the user views, and define system processes and data constraints. The following figure summarizes the centralized design option.

Conceptual Model

Conceptual Model Verification Conceptual Model

Conceptual Model

Conceptual Model

Data Dictionary

Decentralized Design This is used when the data component of the system has a large number of entities and complex relations on which very complex operations are being performed. The following diagram shows the decentralized design.

Programing Assignment Help

Page 3

Data Component

Purchasing

Processing

Sales

Verification

Verification

Aggregation

Data Dictionary

In large and complex projects, the database design cannot be done by only one person.

It is taken care by a team of database designers to tackle a complex database project.

Data Mining and Data Warehousing Data Mining: Data mining is the process of extracting meaningful data from the database or data warehouses or other information repositories and can be provided to the concerned persons whenever it is required. Below diagram can show the process of data mining.

Data mining is done by business users with the assistance of database designer/DBAs.

Programing Assignment Help

Page 4

Data Mining & Presentation

Datawarehouse

Data Flow

DB

DB

Information Repositories

Data mining is the process of extracting the stored information to get the details of orders placed by customers, total number of DVDs available for sale in store, total DVDs sold, orders placed by customer, incomplete orders of customer by viewing the Cart details for customer.

Management users can use the stored information to identify the customer rental patterns, incomplete orders, revenue from rentals, purchase expenses etc.

Data Warehousing: Data warehouse is a place where data collected from different sources are stored. Data warehouse is different from operational database. It provides a simple and concise view on one or more selected areas to support decision process. It obtains data from multiple heterogeneous data sources. It is used to store historical data and provides read only access to the users i.e. Data warehousing is the process of compiling and organizing data into one common database. Data warehousing process is done by engineers/DBAs/database designers.

DB

DB

DB Extraction & Loading

Datawarehouse

DB

Extraction & Loading

Information Repositories

Information Repositories

Data warehousing in our online DVD sales example is to collect the information about DVDs, Customer, Order details, Customer Order History and Customer Credit Card Programing Assignment Help

Page 5

information and then stores all this information in the central data repository. In this case data sources are DVD information, customer information, order information, order history.

In this scenario we are getting DVD information from different sources as DVD can be purchased from different DVD stores and then this information is made available in this database.

Programing Assignment Help

Page 6