lecture dbm1

8/11/2019 Lecture DBM1

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Learning Objectives

IT for Business Management, 2014

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Organisations need to process and organize largeamounts of data. Examples: Marketing manager: access customer data, their web habits and past

purchases

HR manager: Analyze the impact of raises, employee insurance benefitsand retirement contributions on long term costs to a company.

1. Illustrate the importance of managing data and the difficultiesinvolved.

2. Explain the business value of implementing data managementprocesses and technologies in an organization.

3. Outline the advantages of a database management approach tomanaging the data resources of a business, compared to a fileprocessing approach.


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Learning Objectives


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4. Explain how database management software helps

business professionals and supports the operations and

management of a business.

5. Provide examples to illustrate each of the followingconcepts:

Major types of databases.

Data warehouses and data mining.

Logical data elements.

Fundamental database structures.

Database development.


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Why Study Data Management?


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Todays business enterprises cannot survive or succeed without

qualitydata about their internal operations and external

environment.

The goal of data management is to provide the infrastructure

and tools to transform raw data into usable corporate

information of the highest quality.

Managers face constraintsto make intelligent business

decisions.

Data errors and inconsistencies lead to mistakes and lost opportunities,

such as failed deliveries, invoicing blunders, and problems synchronizing

data from multiple locations.

Data analysis errors as a result of inaccurate formulas or untested

models.


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Data Management


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It is a structured approach that applies information

systems technologies for capturing, storing,

processing, integrating, distributing, securing and

archiving data throughout theirlife cycle.


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Data Management: Challenges


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It is difficult to manage, search, and retrieve data located

throughout the enterprise? Reasons:

The volume of data

increases exponentially with time..

External data are constantly increasing in volume.

Data are scattered throughout organizations and are collected and created by

many individuals using different methods and devices.

Data are frequently stored in multiple servers and locations and also in different

computing systems, databases, formats, and human and computer languages.

Data security, quality, and integrity are critical

Legal requirements relating to data differ among countries, and they change

frequently.

Data throughout an organization may be redundant and out-of-date, creating

a huge maintenance problem for data managers.


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Organising Data


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It is essential to organize and maintain data in a

proper way to provide users with accurate, timely

and relevant information.

To understand the problem,

lets first study how systems arrange data in computer

files and traditional methods of file management.

Then, how the problems of traditional file management

are resolved by DBMS software.


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The Hierarchy of Data


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Bit (a binary digit):represents a circuit that is either on

or off

Byte:typically made up of eight bits

Character:a byte represents a character; the basic

building block of information

Can be an uppercase letter, lowercase letter, numeric digit,

or special symbol

Field:typically a name, number, or combination of

characters that describes an aspect of a business object

or activity


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The Hierarchy of Data (continued)


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Record:collection of related data fields

File:collection of related records

Database:collection of integrated and related files

Hierarchy of data

Bits, characters, fields, records, files, and databases


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Database


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Database:A database is a collection of information

organized in such a way that a computer program

can easily record and retrieve it.

Databases are organized into files, records, and fields.

Two basic types:

Centralized

Distributed Replicated

Partitioned


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DBMS


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Database management system (DBMS):group of

programs to manage database

Manipulates database

Provides an interface between database and the user

of the database and other application programs

Database administrator (DBA): skilled IS

professional who directs all activities related to anorganizations database


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Data Entities, Attributes, and Keys


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Entity: generalized class of people, places, or

things (objects) for which data is collected, stored,

and maintained Attribute:characteristic of an entity

Data item: specific value of an attribute

Key: field or set of fields in a record that is used to

identify the record

Primary key:field or set of fields that uniquely

identifies the record


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Data Entities, Attributes, and Keys


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Keys and Attributes


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Logical Data Elements


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Traditional File Processing


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Definition:

Data are organized, stored, and processed in independent files ofdata records


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Problems of File Processing


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Data Redundancy same piece of data could be duplicated inseveral places by several applications

Leads to data inconsistency and data integrity

Program-Data DependenceIt refers to the coupling of data storedin files and the specific programs required to update and maintainthose files such that changes in programs require changes to the data

Lack of flexibility - A traditional file system can deliver routinescheduled reports after extensive programming efforts, but it cannotdeliver ad hoc reports or respond to unanticipated informationrequirements in a timely fashion.

Poor Securitydifficult to enforce Lack of Data sharing and availability- Because pieces of information

in different files and different parts of the organization cannot berelated to one another, it is virtually impossible for information to beshared or accessed in a timely manner.


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Database Management Approach


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Consolidates data records into one database thatcan be accessed by many different applicationprograms.

Software interface between users or applicationprograms and databases

Data definition is stored once, separately fromapplication programs


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Database Management Approach


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The Database Approach (continued)


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Advantages of the Database Approach


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Advantages of the Database Approach (continued)


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Disadvantages of the Database Approach

lecture dbm1

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