Data bases and Data warehouses

Week 7 Questions

1. List, describe, and provide an example of each of the five characteristics of high quality information.

· Accuracy: the extent to which something is accurate e.g. are names spelled correctly?

· Completeness: are values in database compete e.g. is the address fully complete include postcode etc.

· Consistency: are certain types of information in agreement with each other? E.g. total felids equalling true total of individual fields.

· Uniqueness: does information only appear once? E.g. are there any duplicate customers?

· Timelessness: is information current e.g. is it updated on a weekly basis.

2. Define the relationship between a database and a database management system.

A database maintains information about various types of objects, event, people and places. While a database management system (DBMS) is a computer program used to manage and query a database.

3. Describe the advantages an organisation can gain by using a database.

Increased flexibility- good databases can handle changes quickly and easily.

Increase scalability and performance- databases today scale to exceptional levels, allowing all types of users and programs to perform information=processing and information searching tasks.

Reduced information redundancy- this can be achieved by recording each piece of information in only one place in the database.

Increased information integrity- the specification and enforcement of integrity constraints produce higher quality information.

Increased information security- provide security features including; passwords, access levels and access controls.

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.

Database fundamentals include:

· Entities and attributes- an entity in the relational database model is a person, place, thing, transaction or event about which information is stored. While attributes are characteristics or properties of an entity class.

· Keys and relationships- a primary key is a field that uniquely identifies a given entity in a table. While a foreign key is a primary key of one table that appears as an attribute in another table and acts to provide a logical relationship between the 2 tables.

5. Describe the benefits of a data-driven website.

- Allows the reader to make changes anytime and develop it easily.

- Does not require a programmer to make updates

- Enables the site to grow faster then would be possible with a static site.

- Minimisers human error

- Cuts down production and updating costs

- Efficient at keeping volumes of information intact

- Improved stability

6. Describe the roles and purposes of data warehouses and data marts in an organisation

A data warehouse is a logical collection of information that supports business analysis activities and decision-making tasks. The main purpose of a data warehouse is to aggregate information throughout an organisation into s single repository in such a way that employees can make decisions and undertake business analysis activities. A data mart contains a subset of data warehouse information.

Week Six - Enterprise Architectures

Chapter 5 - Weekly Questions

Weekly Questions

1. What is information architecture and what is information infrastructure and how do they differ and how do they relate to each other?

Information architecture is a general plan of how I.T is to be used by or within an organisation which is useful for planning. It identifies where and how important information, such as customer records, is maintained and secured. While information infrastructure is the actual implementation of the hardware, software and telecommunications equipment. Therefore they differ and relate because the architecture is the plan while infrastructure is the implementation of the PLAN.

2. Describe how an organisation can implement a solid information architecture

An organisation can implement a solid information architecture by implementing the following:

- Backup and recovery: a backup is an exact copy of systems information. While a recovery is the ability to get a system up and running in the event of a systems crash or failure. A business should choose a backup and recovery strategy that is in line with its business goals.

- Disaster Recovery: this can be a plan that is a detailed process for recovering information in the event of a catastrophic disaster. While the costs will be high during the first few hours of disaster, they will get lower.

- Information security: this can be fulfilled by managing user access and also adopting up-to-date antivirus software and patches.

3. List and describe the five requirement characteristics of infrastructure architecture.

- Flexibility: An organisation must not only think for today but also have a vision for the future. This is done by making the organisation flexible so it can adapt to changing working conditions.

- Scalability: this refers to how well a system can adapt to increased demands.

- Reliability: this ensures that all systems are functioning correctly and providing accurate information. If a system is accurate then it is safe to say that it is reliable as well.

- Availability: addresses how often users can use and access the system. Many businesses have to however come down for maintenance, upgrades or fixes.

- Performance: this measures how quickly a system performs a certain process or transaction. This ensures efficiency, adaptability and effectiveness.

4. Describe the business value in deploying a service oriented architecture

Service orientated architecture is a business-driven IT architectural approach that supports integrating a business as linked, repeatable tasks or services. This adds value to a business as it helps it be innovative by ensuring that IT can adapt quickly, easily and economically to support rapidly changing business needs. It also helps increase flexibility, strengthen I.T architecture and help create connections among information sources.

5. What is an event?

An event is an electronic message indicating that something has happened; it detects threats and opportunities and alerts those who can act on the information. Pioneered by telecommunication and financial services companies, this involves using IT systems to monitor a business process for events that matter—a stock-out in the warehouse or an especially large charge on a consumer’s credit card—and automatically alert the people best equipped to handle the issue.

6. What is a service?

A service contains a set of related commands that can be re-used, it is more like a software product than they are a coding project. Early forms of services were defined at too low a level in the architecture to interest the business, such as simple “print” and “save” services. The new services are being defined at a higher level; they describe such things as “credit check,” “customer information,” and “process payment.” These services describe a valuable business process.

7. What emerging technologies can companies can use to increase performance and utilise their infrastructure more effectively?

Companies can use the following to increase performance and utilise their infrastructure more effectively:

- Virtualisation

- Grid computing.