Week 7: Databases and Data Warehouses

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

• Accuracy, is concerned with whether all the values are correct, e.g. is the name spelt correctly?
• Completeness, is concerned with whether any values are missing, e.g. is the address complete with number, name and postcode?
• Consistency, is concerned with whether aggregate or summary information is in agreement with detailed information, e.g. do all the total fields equal the true total of the individual fields?
• Uniqueness, is concerned with whether each transaction, entity and event is represented only once in the information, e.g. are there any duplicate customers?
• Timeliness, is concerned with whether the information is current with respect to business requirements, e.g. is information updated weekly, daily or hourly?

2. Define the relationship between a database and a database management system.

A database is the structured file consisting of tables, records and fields and a database management system is the system that manages that database, allowing the user to run queries, compile reports etc.

3. Describe the advantages an organisation can gain by using a database.

Using a database has become essential to modern business. The advantages of using a database are that it reduces redundant information (having to store and maintain multiple copies of the same information), increases flexibility, makes systems scalable and increases information integrity (reliable information and information security). A database makes a business more efficient and effective in its operations and provides analytical information discovering trends.

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

A relational database is one that stores information in the form of logically related two-dimensional tables, each consisting of rows and columns. It is the most commonly used database model today, and example of which is Access.

5. Describe the benefits of a data-driven website.

A data-driven database is one that back-ends to a database. The advantages of a data-driven website is that it allows a user to run a query by submitting a form, making it easier and mores simple to find information, the website more competitive and increases customer satisfaction.

6. Describe the roles and purposes of data warehouses and data marts in an organisation.

A data warehouse is a logical collection of information, gathered from many different operational databases, that supports business analysis activities and decision making tasks. A data mart contains a subset of data warehouse information. Data warehouses have a more organisational focus whilst data marts focus on information subsets particular to the needs of a given business unit such as finance.

(Above: http://data-warehouses.net/architecture/datawarehouses.html)