Accuracy - Are all the values correct? Is the name spelt correctly? Is the dollar amount recorded properly?
Completeness- Are any of the values missing? Is the address complete including street, city, state and zip code?
Consistency - Is aggregate or summary information n agreement with detailed information? Do all total fields equal the true total of the individual fields?
Uniqueness - In each transaction, entity and event represented only once in the information? Are there any duplicate customers?
Timelines - Is the information current with respect to the business requirements? Is the information updated weekly, daily or hourly?
Define the relationship between a database and a database management system.
Database : maintains information about various types of objects (inventory), events (transactions), people (employees) and places (warehouses).
Database management system (DBMS) : is software through which users and application programs interact with a database . Think of it this way: A DBMS is to a database as word processing software is to a document or as a spreadsheet software is to a spreadsheet. Its primary task is to allow users to create access and use information stored in a database.
Describe the advantages an organisation can gain by using a database.
Increased flexibility: data bases tend a mirror business structures and a good data base can handle changes quickly and easily, just as any good business needs to be able to handle changes quickly and easily. Data bases provide flexibility in allowing each user to access the formation in whatever way best suits his or her needs.
Physical view : information deals with the physical storage of information on a storage device such as a hard disk
The logical view: of information focuses on how users logically access information to meet their particular business needs.
Increased scalability and performances: Scalability refers to how well a system can adapt to increased demands. Performance measures how quickly a system performs a certain process or transaction.
Reduced redundancy: redundancy is the duplication of information, or storing the same information in multiple places. Redundant information occurs because organisations frequently capture and store the same information in multiple locations
Increased integrity (quality): in a measure of the quality of information. Within a database environment, integrity constraints are rules that help ensure the quality of information. Integrity constraints are defined and built into the data base.
Increased security: as system become increasingly complex and more available over the internet, security becomes an even bigger issue. Data bases offer many security features including : passwords, access levels and access controls
Define the fundamental concepts of the relational database model.
Table : a set of relation records
Record: a collection of data about an individual item
Field: a single item of data common to all records
Describe the benefits of a data-driven website.
-Development of a business
-Content management
-Future expandability
-Minimising human error
-Cutting production and update costs
-More efficient
-Improved stability
Describe the roles and purposes of data warehouses and data mining in an organisation
Data warehouses are a logical collection of information gathered from many different operational databases that support business analysis activities and decision making tasks. It main purpose is to aggregate information throughout an organisation into a single repository for decision making purposes.
Data mining is the process of analysing data to extract information not offered by the raw data alone to perform users need data mining tools such as cluster analysis , association detection and statistical analysis .
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