Data and Knowledge Management

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Nov 6, 2013 (3 years and 7 months ago)

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1

Lecture 7


Data and Knowledge Management



J. S. Chou, P.E., Ph.D.

Assistant Professor

Department of Business Administration

National Chung Cheng University





2

Objectives

1.

Describe why databases have become so
important to organizations


2.
Describe what databases and database
management systems are and how they work


3.
Explain how organizations are getting the most
from their investment in database technologies


4.
Describe what is meant by knowledge
management and knowledge assets as well as
benefits and challenges of deploying a knowledge
management system


3

Database Technology


A collection of related data organized in
a way that makes it valuable and useful


Allows organizations to retrieve, store,
and analyze information easily


Is vital to an organization’s success in
running operations and making
decisions

4

Database Terminology

Entities


Things we store information about. (i.e.
persons, places, objects, events
, etc.)


Have
relationships

to
other entities

(i.e.
the entity Student has a relationship to the
entity Grades in a University Student
database

Attributes


These are
pieces of information

about an
entity

(i.e. Student ID, Name, etc. for the
entity Student)

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Relationship of DBMS Concepts
to Others?

6

Levels of a Database Management System
(DBMS)

Database

Record

File

Field

Individual characteristics about an ENTITY.
Fields are also called attributes or columns
depending on the type of DBMS

Term

A group of fields or attributes to describe a
single instance of an ENTITY. These are
also called rows depending on the DBMS

A collection of records or instances for a
given ENTITY. These are also called tables
depending on the DBMS

A collection of files or entities containing
information to support a given system or a
particular topic area

Term Definitions






Lowest

Highest

Level

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View of a Database Table or File

Attribute

(One Column)

Record

(One

Row)

Attribute

Type

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File Processing vs Database Approach Summary

File Processing Approach (Old School)


Storage Media:

Sequential tapes or files


Data:

stored in long sequential files


Organization:

redundant data in multiple files


Efficiency:

data embedded to support processing


Updates:

requires multiple updates in many files


Processing:

slower query/faster processing

Data Base Approach (New School
-
TODAY)


Storage Media:

Direct Access Storage Device (DASD)


Data:

stored in related tables


Organization:

redundant data minimized/eliminated


Efficiency:

data only stored only in tables


Updates:

requires few or one update for a data field


Processing:

faster query/slower processing

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Roles in Database Development and Use

Database Administrator (DBA)


Designs, develops and monitors
performance of databases


Enforces policy and standards
for data uses and security

Systems Programmer


Creates business applications
that connect to databases


Tests the new systems and
databases before use

Systems Analyst


Defines data requirements
working with a DBA


Incorporates the database
design into new program
designs

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Database Systems Activities


Data Entry

Enter

Forms

Employment

Applications

(Form Entry Screen)

(Form Entry Program)

(Employment DB)

Example


Data is entered from paper employment
applications into a form entry screen


The entry forms are designed to match
the paper forms for easy entry


The form data is processed by the entry
program and then stored in the
employment database

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Database Systems Activities


Query

(Query Request)

(Query Program)

(Employment Query)

SQL (Structure Query Language)


A language to select and extract data from a database


The industry standard language for relational databases

QBE (Query by Example)


A technique that allows a user to design a query on a screen by
dragging and placing the query field in their desired locations

Query



A database function that extracts and displays information
from a database given selection parameters.

Example



Display applicants entered in the last 30 days


Query parameters are selected in the query request screen


The database program uses SQL to query and present the result

12

Database Systems Activities


Report

(Query Request)

(Query Program)

(Employment Report)

Report Generator


A specialized program that uses SQL to retrieve and manipulate
data (aggregate, transform, or group)


Reports are designed using standard templates or can be custom
generated to meet informational needs

Report



A database function that extracts and formats information
from a database for printing and presentation

Example



Report on applicants entered in the last 30 days


Report parameters are selected in the report request screen


The database program uses SQL to query and present the result

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Designing Databases


Data Model

Example: ERD (Entity Relationship Diagram)

Data Model


A map or diagram that represents
entities

and
their
relationships


Used by Database Administrators to design
tables

with their corresponding
associations


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Designing Databases


Keys

Primary Key

A unique attribute type used to identify
a single instance of an entity.

Secondary Key

An attribute that can be used to identify one or more records
within a table with a given value

Compound Primary Key

A unique combination of attributes types used to
identify a single instance of an entity

Database Keys

Mechanisms used to identify, select, and maintain one or
more records using an application program, query, or report

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Designing Databases


Keys (Example)

Primary

Key

-

Student ID

ENTITIES

Compound

Primary Key

-

Student ID

-

Course ID

-

Sec No.

-

Term

Secondary

Key

-

Major

Entities are translated


into Tables

(Students and Grades)

Entities are

joined by

common

attributes

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Designing Databases
-

Associations

Associations



Define the relationships one entity has to another



Determine necessary key structures to access data



Come in three relationship types:


-

One
-
to
-
One


-

One
-
to
-
Many


-

Many
-
to
-
Many

Foreign Key


An attribute that appears as a non
-
primary
key in one entity (table) and as a primary key
attribute in another entity (table)

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Designing Databases
-

Associations

Entity Relationship Diagram (ERD)



Diagramming tool used to express entity relationships


Very useful in developing complex databases

Example



Each Home Stadium has a Team (One
-
to
-
One)



Each Team has Players (One
-
to
-
Many)



Each Team Participates in Games



For each Player and Game there are Game Statistics

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Designing Databases
-

Associations

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Designing Databases


Associations
(Example)

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The Relational Model

The Relational Model


The most
common

type of
database model

used
today in organizations


Is a
three
-
dimensional model

compared to the
traditional two
-
dimensional database models

-

Rows (first
-
dimension)

-

Columns (second
-
dimension)

-

Relationships (third
-
dimension)


The
third
-
dimension

makes this model so powerful
because
any row

of data can be
related

to
any
other row

or rows

of data

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The Relational Model
-

Example

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The Relational Model
-

Normalization

Normalization


A technique to make complex databases more efficient by
eliminating as much redundant data as possible


Example: Database with redundant data (below)

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The Relational Model
-

Normalization

Normalized Database

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The Relational Model


Data Dictionary

Data Dictionary


Is a document that database designers prepare to help
individuals enter data


Provides several pieces of information about each
attribute in the database including:

-

Name

-

Key

(is it a key or part of a key)

-

Data Type

(date, alpha
-
numeric, numeric, etc.)

-

Valid Value

(the format or numbers allowed)


Can be used to enforce
Business Rules

which are
captured by the database designer to prevent illegal or
illogical values from entering the database. (e.g. who has
authority to enter certain kinds of data)

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Online Transactional Processing (OLTP)


Online Transactional Processing


The mechanism by which customers, suppliers, and
employees process business transactions for an organization


These users conduct transactions online through internal
systems and external Websites for processing and storage

Example

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Operational vs Informational
Systems

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Organizational Use of Databases

Department

Databases

Data

Warehouse

Data

Mart

Operational

Informational

Extract

Data

Extract

Data


Day to Day
Department
Transactions


Used primarily by
departments


Extracted
Department
transactions


Used for
business
analysis


Extracted
subset of a data
warehouse


Used for highly
specific business
analysis

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Online Analytical Processing (OLAP)

Online Analytical Processing


Graphical
software tools that provide
complex analysis

of
data

stored on a database


OLAP tools enable users to analyze
different
dimensions

of data
beyond

data summary and data
aggregations of
normal database queries


The
OLAP Server
is the
chief component

of an OLAP
system which understands how the data is
organized

and
has
special functions

for analyzing data


OLAP can provide
time series

and
trend analysis

views
of data,
data
-
drill downs
, and the ability to answer
“what
-
if” and “why”

questions as part of its functions

29

Data Mining

Data Mining


Is a
method

companies use to
analyze information

to
better understand

their customers, products, markets, or
any other phase of their business for which they have
data


With data mining tools you can
graphically drill down
,
sort or extract

data based on
certain conditions
,
perform a variety of
statistical analysis


Data mining applications are very powerful and use highly
complex algorithms

to
analyze

and to
identify
opportunities

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Data Warehouse Example

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Uses of Data Warehousing

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Data Life Cycle Process

Continued

The result
-

generating knowledge


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Data Sources



Internal Data Sources

are usually stored in the corporate database and
are about people, products, services, and processes.


Personal Data

is

documentation on the expertise of corporate employees
usually maintained by the employee. It can take the form of:


estimates of sales


opinions about competitors


business rules


Procedures


Etc.


External Data Sources

range from commercial databases to Government
reports.


Internet and Commercial Database Services

are accessible through the
Internet.

The
data life cycle

begins with the acquisition of data from data sources.
These sources can be classified as internal, personal, and external.

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Methods for Collecting Raw Data




Collection can take place


in the field


from individuals


via manually methods


time studies


Surveys


Observations


contributions from experts


using instruments and sensors


Transaction processing systems (TPS)


via electronic transfer


from a web site (Clickstream)

The task of data collection is fairly complex. Which can create data
-
quality
problem requiring validation and cleansing of data.

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Methods for managing data collection



DFM consists of


a decision support system


a central data request processor


a data integrity component


links to external data suppliers


the processes used by the external data suppliers.

One way to improve data collection from multiple external sources is to use
a
data flow manager (DFM),

which takes information from external sources
and puts it where it is needed, when it is needed, in a usable form.

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Data Quality and Integrity


Intrinsic DQ:

Accuracy, objectivity, believability, and
reputation.


Accessibility DQ:

Accessibility and access security.


Contextual DQ:

Relevancy, value added, timeliness,
completeness, amount of data.


Representation DQ:

Interpretability, ease of understanding,
concise representation, consistent representation.

Data quality

(DQ) is an extremely important issue since quality determines
the data’s usefulness as well as the quality of the decisions based on the
data.
Data integrity

means that data must be accurate, accessible, and up
-
to
-
date.

Data quality is the cornerstone of effective business intelligence.

37

Knowledge Management Definitions

Knowledge Assets

All underlying skills routines, practices, principles, formulas,
methods, heuristics, and intuitions whether explicit or tacit

Tacit Knowledge

The processes and procedures on how to effectively
perform a particular task stored in a persons mind

Explicit Knowledge

Anything that can be documented, archived, or codified
often with the help of information systems

Knowledge Management

The process an organization uses to gain the greatest value
from its knowledge assets

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Knowledge Management System (KMS)

Primary Objective

How to recognize, generate, store, share, manage this tacit
knowledge (Best Practices) for deployment and use

Technology

Generally not a single technology but instead a
collection
of tools

that include
communication technologies

(e.g.
e
-
mail, groupware, instant messaging), and
information
storage

and
retrieval systems

(e.g. database
management system) to meet the
Primary Objective

Best Practices

Procedures and processes that are widely accepted as
being among the most effective and/or efficient

39

Knowledge


Knowledge Management Systems



A functioning knowledge management system follows six steps in a cycle
dynamically refining information over time

1.
Create knowledge.

2.
Capture knowledge.

3.
Refine knowledge.

4.
Store knowledge.

5.
Manage knowledge.

6.
Disseminate knowledge.

The goal of knowledge management is for an organization to be aware of
individual and collective knowledge so that it may make the most effective
use of the knowledge it has. Firms recognize the need to integrate both
explicit and tacit knowledge into a formal information systems
-

Knowledge
Management System (KMS)

As knowledge is disseminated, individuals develop, create, and
identify new knowledge or update old knowledge, which they
replenish into the system.

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Knowledge


Knowledge Management
Systems


Continued

Knowledge
Management Cycle

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Knowledge Management



Information Technology



Components of Knowledge Management
Systems:


Communication technologies

allow users to access needed
knowledge and to communicate with each other.


Collaboration technologies

provide the means to perform group
work.


Storage and retrieval technologies

(
database management systems
)
to store and manage knowledge.


Knowledge management is more than a technology or product, it is a
methodology applied to business practices. However, information technology
is crucial to the success of knowledge management systems.

42

Knowledge Management



Integration

Knowledge management systems integration.

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Benefits and Challenges of
Knowledge Management