Week 7 Databases

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

Accuracy: preventing data entry errors with strictly entering accurate data.

Completeness: if data is incomplete then it's useless since it wouldn't represent an accurate whole image of reality.

Consistency: crucial part of the database approach as same data will be shared through the different departments.

Uniqueness: data has to be unique and pass the data integrity test.

Timeliness: data has to be updated to consistently be reliable.

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

A collection of interrelated data together with a set of programs to access the data, also called database system, or simply database. The primary goal of such a system is to provide an environment that is both convenient and efficient to use in retrieving and storing information.

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

Relational databases minimise errors in several ways. Reduces information redundancy and increases information integrity (quality)

Combines datasets easily and efficiently

Reveal new features of the data: Increased flexibility, Increased information security and Increased scalability and performance. 

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

A database can be understood as a collection of related files. How those files are related depends on the model used. Early models included the hierarchical model , and the network model .

The relational database model was a huge step forward, as it allowed files to be related by means of a common field. In order to relate any two files, they simply need to have a common field, which makes the model extremely flexible.

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

The first and major benefit is that changing the content of the website can be done without specialized knowledge or expertise.

The second benefit is the level of speed when the website manager makes changes.

Thirdly, data-driven websites inherently have a great deal of scalability.

The fourth advantage includes reduced error rate.

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

The purpose of the Data Warehouse in the overall Data Warehousing Architecture is to integrate corporate data.  It contains the "single version of truth" for the organization that has been carefully constructed from data stored in disparate internal and external operational databases.
The amount of data in the Data Warehouse is massive.  Data is stored at a very granular level of detail.  For example, every "sale" that has ever occurred in the organization is recorded and related to dimensions of interest.  This allows data to be sliced and diced, summed and grouped in unimaginable ways.  

Source: http://www.creelprint.com/index.php/history/database-management/