WEEK 9 QUESTIONS

1. What are some of the difficulties in managing data?
Difficulties in managiing data include:
- the amount of data increases exponentially with time
- data is often scattered throughout the organisation and is handled by many individuals
- data comes from many different sources (internal, personal and external), therefore it is hard to keep a track of the data
- data decays over time

2. What are the various sources for data?
There are 3 main sources of data. These are internal sources (corporate databases), personal sources (personal thoughts, opinions and experiences) and external sources (commercial databases, government reports etc)

3. What is a primary key and a secondary key?
A primary key is the identifier field or attribute that uniquely identifies a record. A secondary key is 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?
An entity is a person, place, thing, or event about which information is maintained in a record. There are 3 types of relationships:
- one to one: a single-entity instance of one type is related to a single-entity instance of another type
- one-to-many: for example, a professor can have many courses, but each course can only have one professor
- many-to-many: for example, a student can have many courses, and a course can have many students

5. What are the advantages and disadvantages of relational databases?
An advantage of relational databases is that it is usually designed with a number of related tables, which means there is not too much data redundancy. It also allows for flexibility in the variety of queries they can make.
A disadvantage is because large-scale databses can be composed of many interrelated tables, the overall design can be complex and therefore hace slow search and access times

6. What is knowledge management?
Knowledge Management is a process that helps organisations identify, select, organise, disseminate, transfer, and apply information and expertise that are part of the organisation's memory and that typically reside within the organisation in an instructured manner

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