Week 7 Questions

1.
Accuracy: Are all the values correct in the data correct and accurate.
Completeness: Are all the values complete in the data.
Consistency: Is the aggregate or summary information in agreement with detailed information.
Uniqueness: Is each transaction, entity, and event represented only once in the information.
Timeliness: Is the information Current with respect to the business requirements.

2.
A Database is a organised collection of data where a database management system (DBMS)is a group of programs that manipulate the database and provide an interface between the database and its users and other application programs.

3.
Databases can help prevent the following
Data redundancy: The same data are stored in many places.
Data isolation: Applications cannot access data associated with other applications.
Data inconsistency: Various copies of the data do not agree.
Datebases also ensure the following
Data security: Keeping the organization’s data safe from theft, modification, and/or destruction.
Data integrity: Data must meet constraints (e.g., student grade point averages cannot be negative).
Data independence: Applications and data are independent of one another. Applications and data are not linked to each other, meaning that applications are able to access the same data.

http://www.youtube.com/watch?v=KqvIGYjcLQ4&feature=related

4.
A relational database is a collection of tables from which data can be accessed in many different ways without having to reorganize the database tables.

5.
Data-driven websites are an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database. The advantages of a data-driven website are as follows:
Development
Content management
Future expandability
Minimising human error
Cutting production and update costs
More efficient
Improved stability
Real time info like stock levels & price changes

6.
The primary purpose of a data warehouse is to aggregate information throughout an organisation into a single repository for decision-making purposes