Database

8.1

LEARNING OBJECTIVESLEARNING OBJECTIVES• COMPARE TRADITIONAL FILE COMPARE TRADITIONAL FILE

ORGANIZATION & MANAGEMENT ORGANIZATION & MANAGEMENT TECHNIQUESTECHNIQUES

• EXPLAIN PROBLEMS OF TRADITIONAL EXPLAIN PROBLEMS OF TRADITIONAL FILE ENVIRONMENTFILE ENVIRONMENT

• DESCRIBE HOW DATABASE MANAGEMENT DESCRIBE HOW DATABASE MANAGEMENT SYSTEM SYSTEM ORGANIZES DATAORGANIZES DATA

• DISCUSS NEW DISCUSS NEW DATABASE DATABASE TRENDSTRENDS

**

8.2

CONTENTSCONTENTS

• TRADITIONAL DATA FILE TRADITIONAL DATA FILE ENVIRONMENTENVIRONMENT

• DATABASE ENVIRONMENTDATABASE ENVIRONMENT

• DESIGNING DATABASESDESIGNING DATABASES

• DATABASE TRENDSDATABASE TRENDS

**

8.4

FILE ORGANIZATIONFILE ORGANIZATION

• BIT:BIT: Binary Digit (0,1;Y,N;On, Off)Binary Digit (0,1;Y,N;On, Off)

• BYTE:BYTE: Combination of BITS which Combination of BITS which represent a CHARACTERrepresent a CHARACTER

• FIELD:FIELD: Collection of BYTES which Collection of BYTES which represent a DATUM or Factrepresent a DATUM or Fact

• RECORD:RECORD: Collection of FIELDS which Collection of FIELDS which reflect a TRANSACTIONreflect a TRANSACTION

**8.5

FILE ORGANIZATIONFILE ORGANIZATION

• FILE:FILE: A Collection of Similar A Collection of Similar RECORDSRECORDS

• DATABASE:DATABASE: A Group of Related A Group of Related Files - An Organization’s Electronic Files - An Organization’s Electronic Library of FILESLibrary of FILES

**

8.5

FILE ORGANIZATIONFILE ORGANIZATION

• ENTITY:ENTITY: Person, Place, Thing, Event Person, Place, Thing, Event about Which Data Must be Keptabout Which Data Must be Kept

• ATTRIBUTE:ATTRIBUTE: Each Characteristic Each Characteristic describing a Particular ENTITYdescribing a Particular ENTITY

**

8.7

KEY FIELDKEY FIELD

Field in Each RecordField in Each Record

Uniquely Identifies THIS RecordUniquely Identifies THIS Record

For For RETRIEVALRETRIEVAL

UPDATINGUPDATING

SORTINGSORTING

**

8.8

SEQUENTIAL VS. DIRECTSEQUENTIAL VS. DIRECTFILE ORGANIZATIONFILE ORGANIZATION

• SEQUENTIAL:SEQUENTIAL: Data records must be Data records must be retrieved in the same physical sequence retrieved in the same physical sequence in which they are stored - Tape Oriented; in which they are stored - Tape Oriented; One File Follows another; Follows One File Follows another; Follows Physical SequencePhysical Sequence

• DIRECT:DIRECT: Disk Oriented; Can be Disk Oriented; Can be Accessed Without Regard to Physical Accessed Without Regard to Physical SequenceSequence

**8.9

• DATA REDUNDANCYDATA REDUNDANCY• PROGRAM / DATA DEPENDENCYPROGRAM / DATA DEPENDENCY• LACK OF FLEXIBILITYLACK OF FLEXIBILITY• POOR SECURITYPOOR SECURITY• LACK OF DATA- LACK OF DATA- SHARING SHARING

& & AVAILABILITYAVAILABILITY

**

TRADITIONAL FILE TRADITIONAL FILE ENVIRONMENT (FLAT FILE)ENVIRONMENT (FLAT FILE)

8.12

BASE DE DATOSBASE DE DATOSUn grupo de datos organizados para Un grupo de datos organizados para servir muchas aplicaciones al mismo servir muchas aplicaciones al mismo tiempo guardando y administrando tiempo guardando y administrando

los datos en forma centralizada.los datos en forma centralizada.

**

8.13

DATABASEDATABASE

ORGANIZATION’S ELECTRONIC ORGANIZATION’S ELECTRONIC LIBRARYLIBRARY

STORES & MANAGES DATASTORES & MANAGES DATA

IN A CONVENIENT FORMIN A CONVENIENT FORM

**

8.13

DATABASE MANAGEMENT DATABASE MANAGEMENT SYSTEM (DBMS)SYSTEM (DBMS)

SOFTWARE TO CREATE & MAINTAIN SOFTWARE TO CREATE & MAINTAIN DATA DATA

ENABLES BUSINESS APPLICATIONS ENABLES BUSINESS APPLICATIONS TO EXTRACT DATA TO EXTRACT DATA

INDEPENDENT OF SPECIFIC INDEPENDENT OF SPECIFIC COMPUTER PROGRAMS COMPUTER PROGRAMS

**

8.14 DBMS

DATABASE MANAGEMENT DATABASE MANAGEMENT SYSTEM (DBMS)SYSTEM (DBMS)

Cuando el programa de aplicación pide Cuando el programa de aplicación pide un ítem de dato (ej: TE de un cliente) el un ítem de dato (ej: TE de un cliente) el DBMS encuentra el ítem de dato en la DBMS encuentra el ítem de dato en la base de datos y se lo entrega al base de datos y se lo entrega al programa. El DBMS elimina la mayoría programa. El DBMS elimina la mayoría de las sentencias de definición de de las sentencias de definición de datos que contenían los programas datos que contenían los programas tradicionales (entorno de archivos tradicionales (entorno de archivos tradicional)tradicional)

8.14 DBMS

COMPONENTS OF DBMS:COMPONENTS OF DBMS:

• DATA DEFINITION LANGUAGE:DATA DEFINITION LANGUAGE:– Defines Data Elements in DatabaseDefines Data Elements in Database

• DATA MANIPULATION LANGUAGE:DATA MANIPULATION LANGUAGE:– Manipulates Data for ApplicationsManipulates Data for Applications

• DATA DICTIONARY:DATA DICTIONARY:– File that stores definitions of data elements File that stores definitions of data elements

and data characteristics such as physical and data characteristics such as physical representation, usage, security, etc.representation, usage, security, etc.

8.15 DBMS

STRUCTURED QUERY STRUCTURED QUERY LANGUAGE (SQL)LANGUAGE (SQL)

EMERGING STANDARD EMERGING STANDARD

DATA MANIPULATION LANGUAGEDATA MANIPULATION LANGUAGE

FOR RELATIONAL DATABASESFOR RELATIONAL DATABASES

**

8.16 DBMS

DATA ELEMENT = FIELDDATA ELEMENT = FIELD

TABLE = FILETABLE = FILE

8.16 DBMS

ADVANTAGES OF DBMS:ADVANTAGES OF DBMS:

• REDUCES COMPLEXITYREDUCES COMPLEXITY

• REDUCES DATA REDUNDANCY / REDUCES DATA REDUNDANCY / INCONSISTENCYINCONSISTENCY

• CENTRAL CONTROL OF DATA CENTRAL CONTROL OF DATA CREATION / DEFINITIONSCREATION / DEFINITIONS

• REDUCES PROGRAM / DATA REDUCES PROGRAM / DATA DEPENDENCEDEPENDENCE

**8.18 DBM

S

ADVANTAGES OF DBMS:ADVANTAGES OF DBMS:

• REDUCES DEVELOPMENT / REDUCES DEVELOPMENT / MAINTENANCE COSTSMAINTENANCE COSTS

• ENHANCES SYSTEM FLEXIBILITYENHANCES SYSTEM FLEXIBILITY

• INCREASES ACCESS / INCREASES ACCESS / AVAILABILITY OF INFORMATIONAVAILABILITY OF INFORMATION

**

8.19 DBMS

3 DATABASE MODELS3 DATABASE MODELS

• HIERARCHICAL DATABASE MODELHIERARCHICAL DATABASE MODEL

• NETWORK DATABASE MODELNETWORK DATABASE MODEL

• RELATIONAL DATABASE MODELRELATIONAL DATABASE MODEL

**

8.20 DBMS

RELATIONAL DATA MODELRELATIONAL DATA MODEL

• DATA IN TABLE FORMATDATA IN TABLE FORMAT

• RELATION:RELATION: TABLE TABLE

• TUPLE:TUPLE: ROW (RECORD) IN TABLE ROW (RECORD) IN TABLE

• FIELD:FIELD: COLUMN (ATTRIBUTE) IN TABLE COLUMN (ATTRIBUTE) IN TABLE

**CODIGO NOMBRE TELEFONO CP

1 J. PEREZ 503-8388 14192 G. CARRARO 316-6936 10063 A. LOPEZ 909-8167 14524 F. BUSTOS 313-4477 1466

8.24

CREATING A DATABASECREATING A DATABASE

• CONCEPTUAL DESIGNCONCEPTUAL DESIGN

• PHYSICAL DESIGNPHYSICAL DESIGN

**

8.28

CREATING A DATABASECREATING A DATABASECONCEPTUAL DESIGN:CONCEPTUAL DESIGN:• ABSTRACT MODEL, BUSINESS ABSTRACT MODEL, BUSINESS

PERSPECTIVEPERSPECTIVE

• HOW WILL DATA BE GROUPED?HOW WILL DATA BE GROUPED?

• RELATIONSHIPS AMONG ELEMENTSRELATIONSHIPS AMONG ELEMENTS

• ESTABLISH END-USER ESTABLISH END-USER NEEDSNEEDS

**

8.29

CREATING A DATABASECREATING A DATABASEPHYSICAL DESIGN:PHYSICAL DESIGN:• DETAILED MODEL BY DATABASE DETAILED MODEL BY DATABASE

SPECIALISTS SPECIALISTS

• ENTITY-RELATIONSHIP DIAGRAMENTITY-RELATIONSHIP DIAGRAM

• NORMALIZATIONNORMALIZATION

• HARDWARE / HARDWARE / SOFTWARESOFTWARE SPECIFICSPECIFIC

**8.30

ENTITY- RELATIONSHIP ENTITY- RELATIONSHIP DIAGRAMDIAGRAM

1

M

M

1

ORDER

CAN HAVE

PART

SUPPLIER

CAN HAVE

ORDER: #, DATE, PART #, QUANTITY

PART: #, DESCRIPTION, UNIT PRICE, SUPPLIER #

SUPPLIER: #, NAME, ADDRESS

8.31

NORMALIZATIONNORMALIZATIONPROCESS OF CREATING SMALL DATA PROCESS OF CREATING SMALL DATA

STRUCTURES FROM COMPLEX STRUCTURES FROM COMPLEX GROUPS OF DATAGROUPS OF DATA

EXAMPLES:EXAMPLES:

• ACCOUNTS RECEIVABLEACCOUNTS RECEIVABLE

• PERSONNEL RECORDSPERSONNEL RECORDS

• PAYROLLPAYROLL

**

8.32

DATABASE TRENDSDATABASE TRENDS

• DISTRIBUTED PROCESSING:DISTRIBUTED PROCESSING: Multiple Multiple Geographical / Functional Systems Geographical / Functional Systems Connected with NetworkConnected with Network

• DISTRIBUTED DATABASE:DISTRIBUTED DATABASE: Data Data Physically Stored in more than one Physically Stored in more than one LocationLocation– PARTITIONEDPARTITIONED– DUPLICATEDUPLICATE

**8.33

DISTRIBUTED DATABASESDISTRIBUTED DATABASES

• PARTITIONED:PARTITIONED: remote CPUs (connected remote CPUs (connected to host) have only the files necessary to to host) have only the files necessary to that site, e.g., records on local that site, e.g., records on local customerscustomers

• DUPLICATE:DUPLICATE: each remote CPU has each remote CPU has copies of common files, copies of common files, e.g., layouts for standard e.g., layouts for standard reports reports and formsand forms

**8.34

DATABASE TRENDSDATABASE TRENDS• HYPERMEDIA:HYPERMEDIA: Nodes Contain Text, Nodes Contain Text,

Graphics, Sound, Video, Programs. Graphics, Sound, Video, Programs. Organizes Data as Nodes.Organizes Data as Nodes.

**

8.35

DATABASE TRENDSDATABASE TRENDS

• MULTIDIMENSIONAL:MULTIDIMENSIONAL: 3D (or higher) 3D (or higher) Groupings to Store Complex DataGroupings to Store Complex Data

• ON-LINE ANALYTICAL PROCESSING ON-LINE ANALYTICAL PROCESSING (OLAP):(OLAP): ability to manipulate and ability to manipulate and analyze large volumes of data from analyze large volumes of data from multiple perspectivesmultiple perspectives

**

8.38

DATABASE TRENDSDATABASE TRENDS• DATA WAREHOUSE:DATA WAREHOUSE: A database, with A database, with

reporting and query tools that stores current reporting and query tools that stores current & historical data extracted from various & historical data extracted from various operational systems and consolidated for operational systems and consolidated for management reporting & analysismanagement reporting & analysis

• DATA MART:DATA MART: small data warehouse for small data warehouse for special function, e.g., special function, e.g., focused focused marketing based marketing based on customer infoon customer info

**

8.36

COMPONENTS OF DATA WAREHOUSECOMPONENTS OF DATA WAREHOUSE

INFORMATIONDIRECTORY

INTERNALDATASOURCES

EXTERNALDATASOURCES

OPERATIONAL,HISTORICAL DATA

DATA WAREHOUSE

EXTRACT,TRANSFORM

DATAACCESS &ANALYSIS

QUERIES &REPORTS

OLAP

DATA MINING

8.37

DATA WAREHOUSEDATA WAREHOUSEThe data originate in many core operational systems and The data originate in many core operational systems and

external sources and are copied into the data warehouse as external sources and are copied into the data warehouse as often as needed - daily, weekly, etc. The data are standardized often as needed - daily, weekly, etc. The data are standardized and consolidated so that they can be used across the and consolidated so that they can be used across the enterprise for management analysis and decision making. enterprise for management analysis and decision making. The data are available for anyone to access as needed but The data are available for anyone to access as needed but cannot be altered. A data warehouse system include a range cannot be altered. A data warehouse system include a range of ad hoc and standardized query tools, analytical tools, and of ad hoc and standardized query tools, analytical tools, and graphical reporting facilities. Enables to access data without graphical reporting facilities. Enables to access data without affecting the performance of the underlying operational affecting the performance of the underlying operational systems.systems.

**

8.38

DATABASE DATABASE ADMINISTRATIONADMINISTRATION

• DEFINES & ORGANIZES DATABASE DEFINES & ORGANIZES DATABASE STRUCTURE AND CONTENTSTRUCTURE AND CONTENT

• DEVELOPS SECURITY PROCEDURESDEVELOPS SECURITY PROCEDURES• DEVELOPS DATABASE DOCUMENTATIONDEVELOPS DATABASE DOCUMENTATION• MAINTAINS DBMSMAINTAINS DBMS

**

8.40

8.42