Week 8- Databases and Data Warehouses

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

Accuracy: checking if all the values are correct.
(E.g. are the names spelt correctly? Is the dollar amount recorded properly?)


Completeness:  checking if any of the values are missing.
(E.g. is the address complete including street, city, state, postcode?)


Consistency: checking to see if information is aggregate or summary information is in agreement with detailed information. (E.g. do all total fields equal the true total of the individual fields?)


Uniqueness: checking whether each transaction, entity and event represented only once in the information?
(E.g. are there any duplicate customers?"


Timeliness: checking whether the information current with respect to the business requirements?
(E.g. is the information updated weekly, daily or hourly?)

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

A 'database' maintains information about various types of objects (inventories), events (transactions), people (employees) and places (warehouses).

A 'database management system (DBMS) is a computer program used to manage and query a database.

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


Datacase information offers many advantages, including:


Increased flexibility: in allowing each user to access the information in whatever way best suits their needs.

Increased scalability and performance:  'Scalability refers to how well a system can adapt to increased demands. 'Performance' measures how quickly a system performs a certain process or transaction.

Reduced information redundancy: redundancy is the duplication of information, or storing the same information in multiple places.

Increased information integrity: is the measure of the quality of information.

Increased information security: organisations must protect its information from unauthorised users or misuse. As systems become more complex and more available over the Internet, security becomes an even bigger issue. Databases thus offer security features such as passwords and access controls, etc.

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

The 'relational database model' is a type of database that stores information in the form of logically related two-dimensional tables each consisting of rows and columns.

The relationional database fundamentals include:

- entities and attributes and keys and relationships

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

Development: allows the website owner to make changes any time- all without having to rely on a developer or knowing HTML programming.

Content management: a static website requires a programmer to make updates.

Future expandabilty: having a data-driven website enables the site to grow faster than would be possible with a static site. Changing layout, displays, etc is easier with data driven solution.

Minimising 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 correct format.

Cutting production and update costs: a data-driven website can be updated and 'published' by an competent data-entry or administrative person.

More efficient: with a data-driven solution, the system keeps track of the templates, so users do not have to. A data-driven infrastructure will improve the reliability and stability of a website, while greatly reducing the chance of 'breaking' some part of the site when adding new areas.

Improved stability: with a data-driven website, there is peace of mind, knowing that the content is never lost- even if your programmer is.