Week Seven - Databases and Data Warehouses
List, describe, and provide an example of each of the five characteristics of high quality information.
The Five common characteristic of high quality information are:
-Accuracy- database need to have correct information. E.g. is the name spelled correctly
-Completeness-having all necessary or normal information, to allows users to access the full capability of the database. E.g. is the address complete including street, city, state and postcode
-Consistency- the summary of information is in agreement with the detailed information. E.g. do all total fields equal the true total of the individual fields?
-Uniqueness- Each transaction, entity and event represented only once in the information.
E.g. students data is stored in one section and use for many different purposes
-Completeness-having all necessary or normal information, to allows users to access the full capability of the database. E.g. is the address complete including street, city, state and postcode
-Consistency- the summary of information is in agreement with the detailed information. E.g. do all total fields equal the true total of the individual fields?
-Uniqueness- Each transaction, entity and event represented only once in the information.
E.g. students data is stored in one section and use for many different purposes
-Timelessness- the information is current with respect to the business requirements E.g. is information updated weekly, daily or hourly?
Define the relationship between a database and a database management system.
Database is a system intended to organise, store, and retrieve large amounts of data/ information so it can easily be accessed, managed and updated.
Database management system (DBMS) is the software through which users and application programs interact with a database
Describe the advantages an organisation can gain by using a database.
Database advantages a business can gain from databases include:
— Increased flexibility
— Increased scalability and performance
— Reduced information redundancy
— Increased information integrity (quality)
— Increased information security
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 dimension tables each consisting of rows and columns.
Table 1 An example of a relational database model
http://en wikipedia.org/wiki/ File: Relational_Model_2.jpg
Describe the benefits of a data-driven website.
A data- driven website is an interactive website kept constantly updated and relevant to the needs of its customers through the use of a database
Data- driven websites advantages include:
-Development: which allowed the website owner to make changes any time, without having to rely on a developer or knowing HTML programming
-Future expandability: enables the site to grow faster than it would be possible with a static site
-Minimising human error: data-driven website will have 'error- trapping' mechanisms to ensure that required information is filled out correctly and that content is entered an displayed correctly. More efficient and improve stability: when updating or adding new areas into the website, the chance of 'breaking' some part of the site is greatly reduced. Thus assuring that the content is never lost when the site is being updated.
Describe the roles and purposes of data warehouses and data marts in an organisation
Data warehouse is a logical collection of information, gathered from any different operational databases, that supports business analysis activities and decision- making task.
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