chapter 4

Chapter 4

1. What are some of the difficulties in managing data?

1. The amount of data increases exponentially with time
2. Data are frequently stored in numerous servers and locations and in different computing systems.
3. New sources of data (blogs, podcasts) are unstructured, meaning that there content cannot be truly represented in computer record.
4. Data decays over time
5. Data security and quality are crucial yet are easily jeopardized.


2. What are the various sources for data?
1. Internal sources (inside corperate databases)
2. Personal sources (individual thought, opinions and experiences)
3. External sources (commercial databases, government reports)


3. What is a primary key and a secondary key?
· Primary Key: is the identifier field or attribute that uniquely identifies a record.
· Secondary Key: An identifier field or attribute that has some identifying information, but typically does not identify the file with complete accuracy.

4. What is an entity and a relationship?
· Entity: A person, place, thing or event about which information is maintained in a record.
· Relationship: Is the connection between the entities.


5. What are the advantages and disadvantages of relational databases?
A relational database is made up of related tables. Theses tables can be joined when they contain common columns. This feature allows great flexibility in the variety of queries they can make. Despite these features, this model has some disadvantages. Because large-scale databases can be composed of many interrelated tables, the overall design can be complex and therefore have slow search and access times.

6. What is knowledge management?
Is a process that helps organizations identify, select organize and disseminate and transfer and apply information and expertise that are part of the organization memory and that typically reside within the organization in an unstructured manner.

7. What is the difference between tacit knowledge and explicit knowledge?
Explicit knowledge is the more objective, rational and technical types of knowledge whereas tactic knowledge is the cumulative store of subjective or experiential learning; highly personal and hard to formalize knowledge.