Database Management Ch.14-A,B,C,D

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Database ManagementDatabase ManagementCh.14-A,B,C,DCh.14-A,B,C,D

FALL 2000FALL 2000

Rob WolfeRob Wolfe

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5 What is data?What is data?

da-tum n [L, fr. neut. of datus] 1 pl. da-ta : something given or admitted esp. as a basis for reasoning or inference

2 pl. da-tums : something used as a basis for calculating or measuring

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5 Managing DataManaging Data

Paper-based Paper-based record-keeping record-keeping approachapproachPersonal / Less official dataStill viable

Electronic Electronic record-keeping approachesrecord-keeping approachesFile systemsDatabase systems

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5 File SystemsFile Systems

A A file system file system is a collection of is a collection of electronic data files that are electronic data files that are specifically designed for and around specifically designed for and around individual applications.individual applications.

EfficientEfficient InflexibleInflexible Important! - Important! - “Not every “Not every

computerized record-keeping computerized record-keeping system is a database system.”system is a database system.”

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5 File SystemsFile Systems

DF DF DF

R L B

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5 Database SystemsDatabase Systems

A A database systemdatabase system is a computerized is a computerized record-keeping system that maintains record-keeping system that maintains information and makes it available to information and makes it available to multiplemultiple users upon demand. users upon demand. [Date][Date]

RequirementsRequirementsData modelDBADBMS

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5 Data ModelingData Modeling

EntityEntity AttributeAttribute ValueValue InstanceInstance

ID?Nam

e?

Sex?

Address?

Class?

Major?StudentStudent

ID: 1234567Name: Jack JonesClass:2000Sex: MAddr: 123 Main Street ...

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ID: 1234567Name: Jack JonesClass:2000Sex: MAddr: 123 Main Street ...

TableTable FieldField Data ItemData Item RecordRecord

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . .

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TableTable FieldField Data ItemData Item RecordRecord

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . .. . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . .

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Hierarchical Data ModelHierarchical Data Model Network Data ModelNetwork Data Model RelationalRelational Data Model Data Model Object-oriented Data ModelObject-oriented Data Model

Fields

Records

Primary Key

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5 Database Management SystemDatabase Management System

A A Database Management SystemDatabase Management System (DBMS) is a piece of software that (DBMS) is a piece of software that defines the database structure and defines the database structure and performs data manipulation to the performs data manipulation to the records residing in a databaserecords residing in a database

Selection of a DBMS depends on data Selection of a DBMS depends on data model and data management model and data management environment.environment.

Examples … Examples … AccessAccess, , OracleOracle, , SybaseSybase, , DB2DB2, , InformixInformix, , SQLSQL ServerServer

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5 Database AdministratorDatabase Administrator

A A Database AdministratorDatabase Administrator (DBA) is (DBA) is responsible for … responsible for … Data modeling & database establishmentMaintenance of data dictionaryManagement and upgrade of DBMSUser support & trainingDatabase system documentation

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5 When it comes to database When it comes to database systems ...systems ...

Remember these two keywords!Remember these two keywords! IntegrationSharing

These two words make the difference These two words make the difference between between database systemsdatabase systems and and file file systemssystems!!

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5 Database SystemsDatabase Systems

DB

DBMS

B

L

R

DBA

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5 Why Database Systems?Why Database Systems?

Advantages over traditional (paper-Advantages over traditional (paper-based) record-keeping systemsbased) record-keeping systemsCompactSpeedyLess DrudgeryCurrentAvailable

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5 Why Database Systems?Why Database Systems?

Advantages over file systems due to Advantages over file systems due to integration and sharing through integration and sharing through centralized controlcentralized controlReduced RedundancyData integrity (Rid inconsistency)StandardsSecurityBetter Communication

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5 Can you tell them apart?Can you tell them apart?

DatabaseDatabase Database Management System Database Management System

(DBMS)(DBMS) Database SystemDatabase System

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5 Can I call this a database system?Can I call this a database system?

Microsoft AccessMicrosoft Access Personal ComputerPersonal Computer Single UserSingle User

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5 What is a “Data File”?What is a “Data File”?

Possible definitions:Possible definitions:

““A data file is any file that … ”A data file is any file that … ” Contains dataContains data

Documents Spreadsheets Sounds, Graphics, Videos

Not executable!Not executable! Contains information in a uniform Contains information in a uniform

formatformat ID, Name, Phone, etc. Examples: Inventory, Library Catalog

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5 File, Records, Fields, and Data File, Records, Fields, and Data ItemsItems

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5 Common Data TypesCommon Data Types

NumericNumericNumbersMathematical manipulation impliedReal, Integers, etc.

Character or String Character or String AlphanumericName, description, ID

DateDate Logical (Yes or No)Logical (Yes or No) MemoMemo

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An effective data model helps …An effective data model helps …Enter, find, and manipulate dataUnderstand relationships between

entitiesCreate efficient data structure

TechniquesTechniquesShow Entities, Relationships, and

CardinalityEntity-Relationship (E-R) Diagrams

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Entities and RelationshipsEntities and Relationships

Employee DepartmentBelongsto

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CardinalityCardinality ... The number of occurrences ... The number of occurrences that can exist between two record typesthat can exist between two record types

One-to-oneOne-to-one One-to-manyOne-to-many Many-to-Many-to-

manymany

Employee

S.S.N.Employee

Phone No.Employee

Certificate

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5 Is it a good data model?Is it a good data model?

Query1:Query1: Find ID numbers of students Find ID numbers of students in MGT 2006.in MGT 2006.

Query2:Query2: Find Courses that Student Find Courses that Student 12000 is taking.12000 is taking.

Insert:Insert: Add Student 32222, William Add Student 32222, William Gates, an MIS major.Gates, an MIS major.

Delete:Delete: Student 13111 drops MGT Student 13111 drops MGT 2006, which is the only course she 2006, which is the only course she takes.takes.

Update:Update: Student 31111 switches to Student 31111 switches to MIS major.MIS major.

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5 Data ModelsData Models

Hierarchical Data ModelHierarchical Data Model Network Data ModelNetwork Data Model Relational Data ModelRelational Data Model Object-oriented Data ModelObject-oriented Data Model

Course

Student

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5 Hierarchical Data ModelsHierarchical Data Models

Course Instructor Room Time

MGT 2006 Barney B214 MWF 06:00

12000 Day, Ken MIS A 13111 Smith, Doris ACC B 15000 Jones, Mary MKT B

Student ID Name Major Grade

MKT 1000 Bond B201 MWF 12:00

25000 Brown, James ACC A 31111 Dolk, Sean MKT B

LAW 4101 Judy B120 TTH 1:00

12000 Day, Ken MIS B 31111 Dolk, Sean MKT A

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Course StudentLink

Nodes

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5 Network Data ModelNetwork Data Model

MGT 2006 Barney

MKT 1000 Bond

LAW 4101 Judy

A

B

B

A

B

B

A

12000 Day, Ken MIS

13111 Smith, Doris ACC

15000 Jones, Mary MKT

25000 Brown, James ACC

31111 Dolk, Sean MKT

LinkNodes

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MGT 2006 Barney B214 MWF 06:00MKT 1000 Bond B201 MWF 12:00LAW 4101 Judy B120 TTH 1:00

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5 Relational Data ModelRelational Data Model


MGT 2006 Barney B214 MWF 06:00MKT 1000 Bond B201 MWF 12:00LAW 4101 Judy B120 TTH 1:00

12000 Day, Ken MIS13111 Smith, Doris ACC15000 Jones, Mary MKT25000 Brown, James ACC31111 Dolk, Sean MKT

Student ID Name Major

Course Student ID Grade

MGT 2006 12000 AMGT 2006 13111 BMGT 2006 15000 BMKT 1000 25000 AMKT 1000 31111 BLAW 4101 12000 BLAW 4101 31111 A

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5 Software for Data ManagementSoftware for Data Management

Custom Software (Programming Custom Software (Programming Languages)Languages)

File management SoftwareFile management Software DBMSDBMS Web-Enabled SoftwareWeb-Enabled Software

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5 Object-Oriented DBMSObject-Oriented DBMS

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5 Web-Enabled ToolsWeb-Enabled Tools

Common Gateway Interface (CGI )Common Gateway Interface (CGI ) allows you to pass requests from the allows you to pass requests from the Web browser to the database and Web browser to the database and back again using programs written in back again using programs written in languages such as Perl, C, and Visual languages such as Perl, C, and Visual Basic.Basic.

Web application development tools Web application development tools provide a way to link HTML pages to provide a way to link HTML pages to a database without programming. a database without programming. (E.g., Cold Fusion)(E.g., Cold Fusion)

Database Management Ch.14-A,B,C,D

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