Chapter 4: Data and Knowledge Management

1. What are some of the difficulties in managing data?
- The amount of data increases exponentially with time
-Data are scattered throughout orgabisations and are collected by many individuals using various methods and devices. Data are frequently stored in numerous servers and locations and in different computing systems, databases, formats and human and computer languages.
-Data decays overtime. E.g. customer smove, new producrs aredeveloped.
Data security, quality and integrity are critical, yet easily jeopardized.

2. What are the various sources for data?
-Internal Data
-External Data
-Personal Data


3. What is a primary key and a secondary key?
Primary Key: the identifier field or attribute that uniquely identifies a record. E.g. Customer ID Number.

Secondary Key: an identifier field or attribute that has some identifying information, but typically does not identify the file with complete accuracy. E.g. a students major, if a user wnted to find all students in a particular major field of study.

4. What is an entity and a relationship?
Entity-relationship (ER) diagram: Document that shows data entities and attributesn and relationships among them.

Entity-relationship (ER) modeling: the preocess of designmng a database by organisaing data entities to be used and identifying the relationships among them.

5. What are the advantages and disadvantages of relational databases?
Advantages
- allow you to manage your data more efficently, avoid errors, and manipulate it easily.
-related tables can be joined when they contain common columns.
The uniqueness of the primary key tells the DBMS which records are joined with others in related tables. This feature allows users great flexibility in the variety of queries they can make.

Disadvantages
Because large-scale databases cn be composed of many interelated tabls, the overall design can be complex and therefore have slow search and access times.


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

7. What is the difference between tacit knowledge and explicit knowledge?
Tacit Knowledge: The cumulative store of subjective or experiential learning; highly personal and hard to formanlize knowledge.

Explicit Knowledge: The more objective, rational, and technical types of knowledge.