There are several characteristics of high quality information.
1. Accuracy. eg. are all the values correct? Is the name spelled correctly? Is the dollar amount recorded properly?
2. Completeness. Is the data missing any relevant information? For example, is the address complete, including street, city, state, and zip code?
3. Consistentcy. eg. Is summary information in agreement with detailed information? Put simply do all total fields equal the true total of the individual fields?
4. Uniqueness. eg. Is each transaction, entity, and event represented only once in the information? ‘are there any duplicate customers?’
5. Timeliness – is the information current with respect to the business requirements? eg. is information updated weekly, daily, or hourly?
2. Define the relationship between a database and a database management system.
The relationship between a database and a database management system can be broken down into two distinct categories. This first of these being direct interaction allows the user to interact directly with the Data Base Management System, which then in turn, obtains the information from the database. The second category, the indirect interaction allows the user to interact with an application such as a sales application. This application then interacts with the data base management system which subsequently obtains the information from the database.
3. Describe the advantages an organisation can gain by using a database.
There are six advantages that an organization can gain from using a database. The first advantage of using a database is that it increases flexibility as a well-designed database should be able to handle changes quickly and easily while providing its users with different views while further maintaining only one physical view. It should however have multiple logical views. The second advantage is linked with the third, these being an increased scalability and performance which will allow an organizations database to meet increased demand, while maintaining acceptable performance levels. The fourth advantage of using a database is that it prevents data redundancy, that is, it stops the same data being stored in many places. The fifth advantage ensures the organization that its data meets constraints such as student grade averages cannot be negative. Put simply, it helps ensure the quality of information. The final advantage of an organization using a database is that it increases its information security, that is, it keeps the organisation’s data safe from theft, modification, and/or destruction.
4. Define the fundamental concepts of the relational database model.
The fundamental concept behind the relational database model concerns itself with a collection of tables from which data can be accessed in many different ways without having to reorganize the database tables. That is, once relationships are created, tables can “talk” to each other. We can link the tables to find such things as which teacher is teaching each subject and which item is selling the most on Friday’s. The tables are 2 dimensional that related to each other in order to allow flexibility and visibility over the business. Each table consists of both columns and rows.
5. Describe the benefits of a data-driven website.
- Development
- Content management
- Future expandability
- Minimising human error
- Cutting production and update costs
- More efficient
- Improved stability
6. Describe the roles and purposes of data warehouses and data marts in an organization
Data warehouses: collection of databases that collect business analysis and decision making tasks. The primary purpose is to aggregate information throughout an organisation into a single area in order to make decisions simpler.
Data mart: smaller subset of a database
The purpose of these is to move away from transactional data to get information and visibility across whole firms and produce all data across all functional areas.
No comments:
Post a Comment