Week 9: Chapter 4

Chapter 4: Data and Knowledge Management

1. There are several difficulties in managing data;

1. The amount of data builds up over time.
2. Data may not be stored and managed properly.
3. New data are unstructured, meaning their content cannot be truly represented in a computer record. Such as blogs, podcasts or RFID tags.
4. Data decays over time. Eg. customers move to new addresses or new products are developed etc.
5. Data security, quality and integrity can easily be jeopardised.

Data warehousing and databases can help manage data and resolve these issues.

2. The various sources for data are-

• Internal Data- eg. corporate databases
• External Data- eg. personal thoughts, opinions and experiences
• Personal Data- eg. commercial databases, government reports, and corporate websites.

Data can also come from the Web, in the form of Clickstream Data- those data that visitors and customers produce when they visit a web site and click on hyperlinks.

3. A primary key is the identifier field. It uniquely identifies that record so that it can be retrieved, updated and sorted in the database. The secondary keys are other fields that have some identifying information but typically doesn't identify the file with complete accuracy.
The image above illustates the primary key (key image) in each SQL, and the shared data are linked with secondary keys (diamonds).

Further information on the keys: http://www.dynamicsoftware.com/knowledgebase/whataresoftwarekeys.html

4. An entity can be identified as an attribute of a person, place, thing, or event about which information is maintained in a record. A relationship is an association among two or more entities. Entities are shown as boxes and relationships as diamonds.

5. A relational database is based on the concept of two-dimensional tables - usually called a flat file - that contains all of the records and attributes. An advantage of this allows users to have great flexibility in the variety of queries they can make. However, a disadvantage of this is that a large-scale database can be composed of many interrelated tables, therefore the overall design can be complex and therefore have slow search and access.

6. Knowledge management (KM) is a process that helps organisations manipulate important knowledge that is part of the organisation's memory, usually in an unstructured format.

7. Tacit knowledge is the cumulative store of subjective or experiential learning. In contrast, explicit knowledge deals with more objective, rational and technical knowledge.