1. List describe and provide an example of each of the five characteristics of high quality information.
i) Accuracy is the information correct? For e.g. is a name spelt correctly?, is a post code valid?,
ii) Completeness are any values missing? Eg is an address complete, including street, city, state and zip cod
iii) Consistency is aggregate information in agreement with detailed information. e.g. if where totaling columns or looking for data in a database, is the information consistent for eg do all total fields = the true total of the individual fields.
iv) Uniqueness is each transaction, entity and even represented only once in the information and are there any duplicate customers?
v) Timelieness is information current with respect to the business requirements eg, updated weekly, daily, hourly?
2. Define the relationship between a database and a database management system.
Database: structured set of data showing records, fields/rows, and viewed in various ways. Eg of database, filing cabinet, address book, telephone directory, timetable.
Image available: http://z.about.com/d/databases/1/0/2/7/Overview.jpg. Microsoft Access an example of a database management system that organisations use.
Database Management System: is a software that manages a database and provides all users with access to all the data. The DBMS do tasks like, query generation, manages tables, user access rights, produce reports. Examples include; Microsoft access, SQL, and Oracle amongst many others.
3. Describe the advantages an organisation can gain by using a database.
Databases are useful in that data can be stored in one system without the use of separate word sheets, which can be confusing for the user, hence a database collates all the relevant information into one program.
Other advantages include:
- Increase flexibility – database provide flexibility in that each user is able to access the information in whatever way best suits their needs, that is a user can run a query on a specific need through the database.
- Increase scalability – database are able to scale to handle volumes of information, i.e adapting to increase in demand such as increase in information. Databases now perform up to the standards of many employees trying to access the same system, and trying to obtain and share information.
- Increase information integrity – information integrity is a measure of the quality of information. The database management system ensures that users can never violate these constraints.
- Increase information security – databases offer security features such as passwords, access levels and access controls.
- Reduced Information Redundancy - reduce duplication of information, or storing the same information in multiple places.
4. Define the fundamental concepts of the relational database model.
Relational database model – stores and structures data into a two dimensional table containing columns and rows. Tables are a collection of data, such as a student timetable containing student records (rows) i.e an entity. The student table will relate to other tables, like a class table that contains information about who is in each class, these are attributes, i.e the characteristics or qualities of a particular entity. The two tables will relate to each other via a primary and foreign key. For instance a student number which is a unique primary key, identifying a user at Notre Dame will be in the student table, the number will be in the class table linking you to various classes, the classes will then have a unique ID which links the classes to a lecturer table etc. Thus, the links are known as relationships.
5. Describe the benefits of a data-driven website.
Data Driven Website – is an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database.
- It is faster to search through information.
- More competitive to have data driven website.
- Increase customer satisfaction.
- Future expandability – enabling a website to grow faster
- Minimizing human error – a data driven website will have “error trapping” mechanisms to ensure that required information is filled correctly and content is in its correct format.
- Increase efficiency – volumes of information, and with a data driven website the system keeps track of the templates instead of the user.
- Improved stability – with a data – driven website, the content is never lost.
6. Describe the roles and purposes of data warehouses and data marts in an organization
Data warehouse - logical collection of information i.e mini databases such as finance and production, gathered from many different operational databases that support business analysis activities and decisions in making tasks.
Video: http://www.ehow.com/video_5112690_data-warehouse_.html. What is a data warehouse?
Image available: http://download.oracle.com/docs/cd/B28359_01/server.111/b28318/img/cncpt170.gif
Data marts are subset of an organizational data store. Their roles are that organizations can move away from looking at transactional data into more analytical data, for business decision-making.
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