Sunday, April 17, 2011

Week 7- Databases and Data Warehouse

1. List, describe, and provide an example of each of the five characteristics of high quality information.

Accuracy- How correct is the information you are dealing with? Are all the values correct? For example, is the name spelled correctly? Is the dollar amount received properly?
Completeness- Is all the information finished and complete? Are any of the values missing? For example, is the address complete including street, city, sate and postcode?
Consistency- Is aggregate or summary information in agreement with detailed information? For example, do all the total fields equal the true total of the individual fields?
Uniqueness- Is each transaction, entity and event represented only once in the information? For example, are there any duplicate customers?
Timeless- Is the information current with respect to the business requirements? For example, is information updated weekly, daily or hourly?
2. Define the relationship between a database and a database management system.
A database is an organised/stored collection of data. The databse is the information
A database management system is software through which users and application programs interact with a database. Is the actual application that runs the database.
3. Describe the advantages an organisation can gain by using a database.
  • Accurately store records 
  • Distribute information easily
  • Reduce redundancy of information
  • Information integrity- high quality information
  • You can make your information secure- allows you to provide authorization to people who need it.

4. Define the fundamental concepts of the relational database model.

  • Entity- Person, place, thing or event. A record generally describes an entity 
  • Attribute- Characteristic or quality of a particular entity
  • Primary key- A unique identifier, for example: a student number
  • Foreign key- A primary key that appears in another table that links the two tables together. 
5. Describe the benefits of a data-driven website.
A data driven website is an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.
The benefits are:
  • Development: allows the website owner to make changes any time all without having to rely on a developer or knowing HTML programming. A well structured, data-driven website enables updating with little or no training. 
  • Content Management: a static website requires a programmer to make updates. This adds an unnecessary layer between the business and its web content, which can lead to misunderstandings and slow turnarounds for desired changes.
  • Future expandability: having a data-driven website enables the site to grow faster than would be possible with a static site. Changing the layout, displays and functionality of the site (adding more features and sections) is easier with a data-driven solution.
  • Minimizing human error: a well designed data-driven website will have ‘error-trapping’ mechanisms to ensure that required information is filled out correctly and that content is entered and displayed in its correct format.

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