8. 8.MANAGINGDATARESOURCES MANAGINGDATARESOURCES 8.1

INFORMATION SYSTEM INFORMATIONSYSTEM BUSINESSCHALLENGE BUSINESSSOLUTIONS MANAGEMENTINFORMATIONTECHNOLOGYORGANIZATION 8.2 OBSTACLES TO DATABASE ENVIRONMENT COST/BENEFIT CONSIDERATIONS PLACING DATA MANAGEMENT FUNCTION

FILE ORGANIZATION BIT: Binary Digit (0,1;Y,N;On, Off)BIT: Binary Digit (0,1;Y,N;On, Off) BYTE: Combination of BITS which represent a CHARACTERBYTE: Combination of BITS which represent a CHARACTER FIELD: Collection of BYTES which represent a DATUM or FactFIELD: Collection of BYTES which represent a DATUM or Fact RECORD: Collection of FIELDS which reflect a TRANSACTIONRECORD: Collection of FIELDS which reflect a TRANSACTION* 8.3

FILE ORGANIZATION FILE: A Collection of Similar RECORDSFILE: A Collection of Similar RECORDS DATABASE: An Organization’s Electronic Library of FILESDATABASE: An Organization’s Electronic Library of FILES* 8.4

FILE ORGANIZATION ENTITY: Person, Place, Thing, Event about Which Data Must be KeptENTITY: Person, Place, Thing, Event about Which Data Must be Kept ATTRIBUTE: Description of a Particular ENTITYATTRIBUTE: Description of a Particular ENTITY KEY FIELD: Field Used to Retrieve, Update, Sort RECORDKEY FIELD: Field Used to Retrieve, Update, Sort RECORD* 8.5

KEY FIELD Field in Each RecordField in Each Record Uniquely Identifies THIS RecordUniquely Identifies THIS Record For RETRIEVALFor RETRIEVAL UPDATING UPDATINGSORTING* 8.6

SEQUENTIAL VS. DIRECT FILE ORGANIZATION SEQUENTIAL: Tape Oriented; One File Follows another; Follows Physical SequenceSEQUENTIAL: Tape Oriented; One File Follows another; Follows Physical Sequence DIRECT: Disk Oriented; Can be Accessed Without Regard to Physical SequenceDIRECT: Disk Oriented; Can be Accessed Without Regard to Physical Sequence* 8.7

FILING METHODS INDEXED SEQUENTIAL ACCESS METHOD (ISAM);INDEXED SEQUENTIAL ACCESS METHOD (ISAM); –EACH RECORD IDENTIFIED BY KEY –GROUPED IN BLOCKS AND CYLINDERS –KEYS IN INDEX VIRTUAL STORAGE ACCESS METHOD (VSAM):VIRTUAL STORAGE ACCESS METHOD (VSAM): –MEMORY DIVIDED INTO AREAS & INTERVALS –DYNAMIC FILE SPACE VSAM WIDELY USED FOR RELATIONAL DATABASES VSAM WIDELY USED FOR RELATIONAL DATABASES DIRECT FILE ACCESS METHODDIRECT FILE ACCESS METHOD* 8.8

DIRECT FILE ACCESS METHOD EACH RECORD HAS KEY FIELDEACH RECORD HAS KEY FIELD KEY FIELD FED INTO TRANSFORM ALGORITHMKEY FIELD FED INTO TRANSFORM ALGORITHM ALGORITHM GENERATES PHYSICAL STORAGE LOCATION OF RECORD (RECORD ADDRESS)ALGORITHM GENERATES PHYSICAL STORAGE LOCATION OF RECORD (RECORD ADDRESS) 8.9

TRADITIONAL FILE ENVIRONMENT (FLAT FILE) DATA REDUNDANCYDATA REDUNDANCY PROGRAM / DATA DEPENDENCYPROGRAM / DATA DEPENDENCY LACK OF FLEXIBILITYLACK OF FLEXIBILITY POOR SECURITYPOOR SECURITY LACK OF DATA SHARING & AVAILABILITYLACK OF DATA SHARING & AVAILABILITY* 8.10

DATABASE ORGANIZATION’S ELECTRONIC LIBRARYORGANIZATION’S ELECTRONIC LIBRARY STORES & MANAGES DATASTORES & MANAGES DATA IN A CONVENIENT FORMIN A CONVENIENT FORM* 8.11

DATABASE MANAGEMENT SYSTEM (DBMS) SOFTWARE TO CREATE & MAINTAIN DATA ENABLES BUSINESS APPLICATIONS TO EXTRACT DATA ENABLES BUSINESS APPLICATIONS TO EXTRACT DATA INDEPENDENT OF SPECIFIC COMPUTER PROGRAMS INDEPENDENT OF SPECIFIC COMPUTER PROGRAMS* 8.12 DBM S

COMPONENTS OF DBMS: DATA DEFINITION LANGUAGE:DATA DEFINITION LANGUAGE: –Defines Data Elements in Database DATA MANIPULATION LANGUAGE:DATA MANIPULATION LANGUAGE: –Manipulates Data for Applications DATA DICTIONARY:DATA DICTIONARY: –Formal Definitions of all Variables in Database; Controls Variety of Database Contents * 8.13 DBM S

STRUCTURED QUERY LANGUAGE (SQL) EMERGING STANDARD DATA MANIPULATION LANGUAGE FOR RELATIONAL DATABASES * 8.14

TWO VIEWS OF DATA BITBYTEFIELDRECORDFILEDATABASE PHYSICAL VIEW: WHERE IS DATA PHYSICALLY?PHYSICAL VIEW: WHERE IS DATA PHYSICALLY? –DRIVE, DISK, SURFACE, TRACK, SECTOR (BLOCK), RECORD –TAPE, BLOCK, RECORD NUMBER (KEY) LOGICAL VIEW: WHAT DATA IS NEEDED BY APPLICATION?LOGICAL VIEW: WHAT DATA IS NEEDED BY APPLICATION? –SUCCESSION OF FACTS NEEDED BY APPLICATION –NAME, TYPE, LENGTH OF FIELD * 8.15

ADVANTAGES OF DBMS: REDUCES COMPLEXITYREDUCES COMPLEXITY REDUCES DATA REDUNDANCY / INCONSISTENCYREDUCES DATA REDUNDANCY / INCONSISTENCY CENTRAL CONTROL OF DATA CREATION / DEFINITIONSCENTRAL CONTROL OF DATA CREATION / DEFINITIONS REDUCES PROGRAM / DATA DEPENDENCEREDUCES PROGRAM / DATA DEPENDENCE* 8.16 DBM S

ADVANTAGES OF DBMS: REDUCES DEVELOPMENT / MAINTENANCE COSTSREDUCES DEVELOPMENT / MAINTENANCE COSTS ENHANCES SYSTEM FLEXIBILITYENHANCES SYSTEM FLEXIBILITY INCREASES ACCESS / AVAILABILITY OF INFORMATIONINCREASES ACCESS / AVAILABILITY OF INFORMATION* 8.17 DBM S

HIERARCHICAL DATABASE ROOT FIRST CHILD 2nd CHILD RatingsSalary Compensation Job Assignments PensionInsuranceHealth Benefits Employer 8.18

POINTER FIELD IN ONE RECORD IS ADDRESS OF NEXT RECORD IN SEQUENCEFIELD IN ONE RECORD IS ADDRESS OF NEXT RECORD IN SEQUENCE POINTER 8.19

TYPES OR RELATIONS ONE-TO-ONE: STUDENT ID ONE-TO-MANY: CLASS STUDENT A STUDENT B STUDENT C MANY-TO-MANY: STUDENT A STUDENT B STUDENT C CLASS 1 CLASS

NETWORK DATA MODEL VARIATION OF HIERARCHICAL MODELVARIATION OF HIERARCHICAL MODEL USEFUL FOR MANY-TO-MANY RELATIONSHIPSUSEFUL FOR MANY-TO-MANY RELATIONSHIPS* 8.21 STUDENT A STUDENT B STUDENT C CLASS 1 CLASS 2

RELATIONAL DATA MODEL DATA IN TABLE FORMATDATA IN TABLE FORMAT RELATION: TABLERELATION: TABLE TUPLE: ROW (RECORD) IN TABLETUPLE: ROW (RECORD) IN TABLE FIELD: COLUMN (ATTRIBUTE) IN TABLEFIELD: COLUMN (ATTRIBUTE) IN TABLE* 8.22

COMPARISON OF DATABASE ALTERNATIVES HIERARCHICAL: PROCESSING EFFICIENCY: HIGH FLEXIBILITY: LOW USER FRIENDLY: LOW PROGRAM COMPLEXITY: HIGH * 8.23

COMPARISON OF DATABASE ALTERNATIVES NETWORK: PROCESSING EFFICIENCY: MEDIUM / HIGH FLEXIBILITY: LOW / MEDIUM USER FRIENDLY: LOW / MODERATE PROGRAM COMPLEXITY: HIGH * 8.24

COMPARISON OF DATABASE ALTERNATIVES RELATIONAL: PROCESSING EFFICIENCY: LOW BUT IMPROVING FLEXIBILITY: HIGH USER FRIENDLY: HIGH PROGRAM COMPLEXITY: LOW * 8.25

CREATING A DATABASE CREATING A DATABASE CONCEPTUAL DESIGNCONCEPTUAL DESIGN PHYSICAL DESIGNPHYSICAL DESIGN* 8.26

CREATING A DATABASE CONCEPTUAL DESIGN: CREATING A DATABASE CONCEPTUAL DESIGN: ABSTRACT MODEL, BUSINESS PERSPECTIVEABSTRACT MODEL, BUSINESS PERSPECTIVE HOW WILL DATA BE GROUPED?HOW WILL DATA BE GROUPED? RELATIONSHIPS AMONG ELEMENTSRELATIONSHIPS AMONG ELEMENTS ESTABLISH END-USER NEEDSESTABLISH END-USER NEEDS* 8.27

CREATING A DATABASE PHYSICAL DESIGN: CREATING A DATABASE PHYSICAL DESIGN: DETAILED MODEL BY DATABASE SPECIALISTSDETAILED MODEL BY DATABASE SPECIALISTS ENTITY-RELATIONSHIP DIAGRAMENTITY-RELATIONSHIP DIAGRAM NORMALIZATIONNORMALIZATION HARDWARE / SOFTWARE SPECIFICHARDWARE / SOFTWARE SPECIFIC* 8.28

ENTITY-RELATIONSHIP DIAGRAM M 1 ORDER CAN HAVE PART SUPPLIER CAN HAVE ORDER: #, DATE, PART #, QUANTITY PART: #, DESCRIPTION, UNIT PRICE, SUPPLIER # SUPPLIER: #, NAME, ADDRESS 8.29

NORMALIZATION PROCESS OF CREATING SMALL DATA STRUCTURES FROM COMPLEX GROUPS OF DATA EXAMPLES: ACCOUNTS RECEIVABLEACCOUNTS RECEIVABLE PERSONNEL RECORDSPERSONNEL RECORDS PAYROLLPAYROLL 8.30

DATABASE TRENDS DISTRIBUTED PROCESSING: Multiple Geographical / Functional Systems Connected with NetworkDISTRIBUTED PROCESSING: Multiple Geographical / Functional Systems Connected with Network DISTRIBUTED DATABASE: Data Physically Stored in more than one LocationDISTRIBUTED DATABASE: Data Physically Stored in more than one Location –PARTITIONED –DUPLICATE * 8.31

DATABASE TRENDS OBJECT- ORIENTED: Data and Procedures Stored Together; can be Retrieved, SharedOBJECT- ORIENTED: Data and Procedures Stored Together; can be Retrieved, Shared HYPERMEDIA: Nodes Contain Text, Graphics, Sound, Video, Programs. Organizes Data as Nodes.HYPERMEDIA: Nodes Contain Text, Graphics, Sound, Video, Programs. Organizes Data as Nodes. MULTIDIMENSIONAL: 3D (or higher) Groupings to Store Complex DataMULTIDIMENSIONAL: 3D (or higher) Groupings to Store Complex Data* 8.32

DATABASE TRENDS DATA WAREHOUSE: Organization’s Electronic Library Stores Consolidated Current & Historic Data for Management Reporting & AnalysisDATA WAREHOUSE: Organization’s Electronic Library Stores Consolidated Current & Historic Data for Management Reporting & Analysis* 8.33

DATABASE ADMINISTRATION DEFINES & ORGANIZES DATABASE STRUCTURE AND CONTENTDEFINES & ORGANIZES DATABASE STRUCTURE AND CONTENT DEVELOPS SECURITY PROCEDURESDEVELOPS SECURITY PROCEDURES DEVELOPS DATABASE DOCUMENTATIONDEVELOPS DATABASE DOCUMENTATION MAINTAINS DBMSMAINTAINS DBMS* 8.34

8. 8.MANAGINGDATARESOURCES MANAGINGDATARESOURCES 8.35