week 8: Databases (Part 2)

Question 1

DATA INTEGRATION

ETL: extract, transform, load

Answer 1

extract data from source systems

transform them

and load them into a data mart or warehouse

Question 2

how can one ETL?

Answer 2

performed by hand-written code (e.g., SQL queries)

by commercial data- integration software

Question 3

“a single version of the truth”

Answer 3

central enterprise data warehouse without data marts

The most common architecture

Question 4

Independent data marts

Answer 4

store data for a single or a few applications

Question 5

Hub and spoke

Answer 5

stores data in a central data warehouse

maintains dependent data marts that obtain their data from the central repository

helps to maintain a single view of the data since it is centrally organized

Question 6

metadata

Answer 6

Data about data

Question 7

The quality of the data in the warehouse must be adequate to?

Answer 7

to satisfy users’ needs

Question 8

what does data governance require?

Answer 8

requires that people, committees, and processes be in place to plan and control the development and use of the data warehouse

Question 9

data users

Answer 9

IT developers

front-line workers

analysts

information workers

managers and executives

suppliers

customers

regulators

Question 10

Knowledge management (KM)

Answer 10

a process that helps organizations manipulate important knowledge that is part of the organization’s memory

Question 11

Knowledge

Answer 11

information that is contextual, relevant, and useful,

developed with the assistance of expertise

also known as Intellectual capital (or intellectual assets)

Question 12

Explicit knowledge

Answer 12

objective, rational, technical knowledge that has been documented

Examples: policies, procedural guides, reports, products, strategies, goals, core competencies

Question 13

Tacit knowledge

Answer 13

cumulative store of subjective or experiential learning

Examples: experiences, insights, expertise, know-how, trade secrets, understanding, skill sets, and learning

Question 14

Knowledge management systems (KMSs)

Answer 14

systematize, enhance and expedite knowledge management

goal is to make the most productive use of knowledge

Question 15

the KMS cycle

Answer 15

1. create
2. capture
3. refine
4. store
5. manage
6. disseminate
7. turns into knowledge
8. create

Question 16

Query Languages

Answer 16

search for information in databases or data warehouses

Question 17

Normalization

Answer 17

optimize the tables in a relational database

Question 18

Joins

Answer 18

link relational database tables with common attributes

Question 19

SQL

Answer 19

Structured Query Language

Question 20

Typical key words from SQL

Answer 20

SELECT (what to locate)

FROM (specify the source files)

WHERE (provides conditions for the search, like an “if” statemen)

Question 21

QBE

Answer 21

Query by Example

Uses a form (template) to provide a sample or description of the desired information

Question 22

entity-relationship (ER) modeling

Answer 22

the database design in a process

consists of entities, attributes and relationships organized using business rules

Entities are shown as rectangles, with relationships shown on the lines between them

Question 23

what do business rules in ER modeling describe?

Answer 23

describe how the organization uses its data to run its operations

Question 24

cardinality

Answer 24

the number of times a single record/instance of one entity can be associated with a single record/instance of another entity

Question 25

types of caridnalities

Answer 25

mandatory single

optional single

mandatory many

optional many

Question 26

optional single (cardinality)

Answer 26

ex: employee wage rate with pay cheque (employees may not be paid if they are on vacation or leave)

Question 27

mandatory many (cardinality)

Answer 27

ex: epartment details with employee details

Question 28

optional many (cardinality)

Answer 28

ex: ustomer details with customer sales details/invoices (not all customers purchase every month)

Question 29

mandatory single (cardinality)

Answer 29

ex: inventory quantity on hand with its sale price

Question 30

normalization

Answer 30

analyzing and reducing a relational database to its most streamlined form

provide minimum redundancy (minimize duplicated attributes)

reduce non-key attributes

Improve processing efficiency of the database