- Accuracy
- Completeness
- Consistency
- Uniqueness - Timeliness
2. Define the relationship between a database and a database management system.
A database is a collection of information that is organised so that it can easily be accessed, managed, and updated. Computer databases typically contain aggregations of data records or files, such as sale transactions, product catalogs and inventories, and customer profiles. An example of a database is Microsoft Access.
A database management system is a set of computer programs that controls the creation, maintenance, and the use of a database. It allows organisations to place control of database development in the hands of database administrators and other specialists. A database management system is a system software package that helps the use of integrated collection of data records and files known as databases. It allows different user application programs to easily access the same databases.
3. Describe the advantages an organisation can gain by using a database.
Databases have many advantages when used by an organisation. These are listed below:
- Data Security - Keeping the organisation's data safe from theft, modification and/or destruction.
- Data Integrity - Data must meet constraints (e.g. student grade point average cannot be negative)
- Data Independence - Applications and data are independent of one another. Applications and data are not linked to each other, meaning that applications are able to access the same data.
- Increased flexibility - should be able to handle changes quickly and easily.
- Increased scalability and performance - a database must scale to meet increased demand, while maintaining acceptable performance levels. Scalability refers to how well a system can adapt to increased demands and performance measures how quickly a system performs a certain process or transaction.
- Reduced information redundancy
- Increased information integrity (quality)
- Increased information security - information is an organisational asset and must be protected. Databases offer several security features including: password (provides authentication of the user), access level (determines who has access to the different types of information) and access control (determines types of user access, such as read-only access).
4. Define the fundamental concepts of the relational database model.
A relational database is 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 (relate) the tables to find: which doctors are seeing a patient, which students are in which class and which item is selling the most on Friday's. Relational databases work on unique records, if you don't have unique records, your database can't tell which record you may be referring to. To ensure that each record is unique in each table, we can set one field to be a primary key field. A primary key field is a field that will contain no duplicates and no blank values.
5. 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. The customer enters the search criteria in the website. The database runs a query on the search criteria. Some of these advantages include: development, content management, future expandability, minimising human error, cutting production and update costs, more efficient and improved stability.
6. Describe the roles and purposes of data warehouses and data marts in an organisation.
Data warehouse is a logical collection of information, gathered from many different operational databases, that supports business analysis activities and decisions-making tasks. The primary purpose of a data warehouse is to aggregate information throughout an organisation into a single repository for decision-making purposes.
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