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Áine MitchellÁine Mitchell– Computer Software Developer / Team Leader / Project managerComputer Software Developer / Team Leader / Project manager– Oracle Database Systems in different OrganisationsOracle Database Systems in different Organisations

– amitchell@itsligo.ie amitchell@itsligo.ie – Room - B1082Room - B1082– Phone - 9155228Phone - 9155228

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Data ManagementData ManagementIntroductionIntroduction

Data ManagementData Management

What is Database and its PurposeWhat is Database and its Purpose

What types of Data Company needs to What types of Data Company needs to storestore

Data as a resourceData as a resource

DBMS – Features and AdvantagesDBMS – Features and Advantages

Functionality of DBMSFunctionality of DBMS

Issues with Data ManagementIssues with Data Management

Centralised Data ManagementCentralised Data Management33

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Traditional File SystemsTraditional File Systems

All automated systems which use data must All automated systems which use data must store this data somewhere.store this data somewhere.Traditionally this data was stored in files.Traditionally this data was stored in files.Each program or application had its own files in Each program or application had its own files in its own formatits own formatIt was difficult to integrate data from different It was difficult to integrate data from different systems. systems. The data and the program were tightly coupled, The data and the program were tightly coupled, so if one changed the other had to change also.so if one changed the other had to change also.– E.g. changing to 8 digit phone numbers.E.g. changing to 8 digit phone numbers.

Purpose of DatabasePurpose of Database

Businesses of every size organize data Businesses of every size organize data records into collections called records into collections called databases.databases.

Small businesses for example use Small businesses for example use databases to keep track of customers databases to keep track of customers

Huge corporations such as Dell and Huge corporations such as Dell and Amazon.com use databases to support Amazon.com use databases to support complex sales, marketing, and operations complex sales, marketing, and operations activitiesactivities

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Huge Quantities of DataModern systems produce huge amounts of data.– EPOS system.– Web retail site– Decision Support Systems– ERP Systems– Enterprise Resource Planning

HR, Financials,Distribution,Product LifeCycle

Customer Relationship Management CRM

Supply Chain – Purchasing, Manufacturing, Distribution

Commercial ApplicationsCommercial ApplicationsManufacturing  Manufacturing  Engineering, bills of material, Engineering, bills of material, scheduling, capacity, workflow management, quality scheduling, capacity, workflow management, quality control, cost management, manufacturing process, control, cost management, manufacturing process, manufacturing projects, manufacturing flowmanufacturing projects, manufacturing flow

Supply chain management  Order to Supply chain management  Order to cash, cash, inventory, order entry, purchasing, product inventory, order entry, purchasing, product configurator, supply chain planning, supplier scheduling, configurator, supply chain planning, supplier scheduling, inspection of goodsinspection of goods, ,

FinancialsFinancials Claim processing, commission calculation Claim processing, commission calculation Financials  General ledger, cash management, accounts Financials  General ledger, cash management, accounts payable, accounts receivable, fixed assets payable, accounts receivable, fixed assets

Commercial ApplicationsCommercial Applications

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Project management  Project management  Costing, billing, time and Costing, billing, time and expense, performance units, activity management expense, performance units, activity management

Human resourcesHuman resources   Human resources, payroll, Human resources, payroll, training, time and attendance, roistering, benefits training, time and attendance, roistering, benefits

Customer relationship managementCustomer relationship management    Sales Sales and marketing, commissions, service, customer contact and marketing, commissions, service, customer contact and call center supportand call center support

Data services  Data services  Various "self-service" interfaces for Various "self-service" interfaces for

customers, suppliers, and/or employeescustomers, suppliers, and/or employees

Access control  Access control  Management of user privileges for Management of user privileges for various processes various processes

Data Requirements ?Data Requirements ?

HSEHSE

City and Guild of London InstituteCity and Guild of London Institute

Company that Manufactures Paper ProductCompany that Manufactures Paper Product

Bórd Na MonaBórd Na Mona

Mulit- National Computer Company Mulit- National Computer Company

CollegeCollege

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Physical and Logical DataPhysical and Logical Data

Logical ViewLogical View– Is concerned with the nature of the data or Is concerned with the nature of the data or

informationinformation– Logical view of a record is a set of data items Logical view of a record is a set of data items

filling the structurefilling the structure

Physical ViewPhysical View– Involves physical aspects of the storage and Involves physical aspects of the storage and

presentationpresentation– How the Data is store, e.g. Employee # char(6)How the Data is store, e.g. Employee # char(6)

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Data as a ResourceData as a Resource

Organisation need to collect and manage Organisation need to collect and manage data to ensure that it can be accessed and data to ensure that it can be accessed and used by people across the organisation.used by people across the organisation.– Handle transactionsHandle transactions– Legal reasonsLegal reasons– Analyse, understand and improve their Analyse, understand and improve their

business.business.– Possible to gain a competitive advantagePossible to gain a competitive advantage

Purpose: to keep track of thingsPurpose: to keep track of things

If structure of a list is simple, i.e., one If structure of a list is simple, i.e., one theme, no need to use database theme, no need to use database technology (video)technology (video)

What Is the Purpose of a What Is the Purpose of a Database?Database?

Form for Recording Multiple Form for Recording Multiple ThemesThemes

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Database Based SystemDatabase Based System

Rather than storing data in file systems Rather than storing data in file systems store it in data bases which can be store it in data bases which can be accessed by a variety of applications.accessed by a variety of applications.

There are rules describing what kind of There are rules describing what kind of data is stored and how it can be accessed data is stored and how it can be accessed and changed.and changed.

The data is independent of the The data is independent of the applications.applications.

Database:Database: A self-describing collection of integrated A self-describing collection of integrated

recordsrecords In databases, In databases,

bytes are grouped into bytes are grouped into columnscolumns, such as , such as Student Student NumberNumber and and Student NameStudent Name. Columns are also . Columns are also called called fieldsfields..

Columns or fields, in turn, are grouped into Columns or fields, in turn, are grouped into rowsrows, , which are also called which are also called records.records.

DatabaseDatabase

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DatabaseDatabase

A A DatabaseDatabase is an is an organisedorganised collection of collection of related data.related data.

There are lots and lots of different ways to There are lots and lots of different ways to organise dataorganise data

Ideal method to organise data would Ideal method to organise data would combine complete flexibility with complete combine complete flexibility with complete control.control.

Hierarchy of DataHierarchy of DataCharacters, Fields, and RecordsCharacters, Fields, and Records

Hierarchy of Data ElementsHierarchy of Data ElementsDatabase is collection of Table or Files

ApplicationsApplications make database data more accessible and make database data more accessible and useful. useful.

Users employ a database application that consists of Users employ a database application that consists of forms, formatted reports, queries, and application forms, formatted reports, queries, and application programs.programs.

Database management system (Database management system (DBMSDBMS) processes ) processes database tables for applicationsdatabase tables for applications..

Components of a Database Components of a Database Application SystemApplication System

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DBMSDBMS

DataBase Management SystemDataBase Management System

A Database with SoftwareA Database with Software for the following: for the following:– Database definitionDatabase definition

Specify the content and structure.Specify the content and structure.

– Data entry and modification.Data entry and modification.– Data processing and report generation.Data processing and report generation.– Provides an interface to user programs (e.g. SQL).Provides an interface to user programs (e.g. SQL).– Security.Security.– RecoveryRecovery– Centralized Control over the DataCentralized Control over the Data

DBMS ProductsDBMS Products

DB2 (from IBM)DB2 (from IBM) MySQL (a free, open source DBMS)MySQL (a free, open source DBMS) Oracle (from Oracle Corporation)Oracle (from Oracle Corporation) SQL Server (from Microsoft)SQL Server (from Microsoft) ASE (from Sybase Corporation)ASE (from Sybase Corporation) Access (from Microsoft)Access (from Microsoft)

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Advantages of using a DBMSAdvantages of using a DBMSSeparates the data from the programmes Separates the data from the programmes using the data.using the data.

Reduces data redundancy and Reduces data redundancy and inconsistency.inconsistency.

Reduces costs of developing new Reduces costs of developing new applications.applications.

Improves the flexibility of the information Improves the flexibility of the information systemssystems

Security can be improvedSecurity can be improved

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Desired functionality in a DBMSDesired functionality in a DBMS

What do you want from your data What do you want from your data management system?management system?– Database DefinitionDatabase Definition– Data AccessData Access– Data ManagementData Management

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Database DefinitionDatabase Definition

Need to be able to define the database Need to be able to define the database structure and the contents.structure and the contents.What records can be stored.What records can be stored.

What fields there are.What fields there are.

What the relationship between the records is.What the relationship between the records is.

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Data AccessData Access

Inserting new dataInserting new data

Searching for dataSearching for data

Generating reportsGenerating reports

Updating data already stored.Updating data already stored.

Deleting data.Deleting data.

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Data AccessData Access

Speed of AccessSpeed of AccessDepending on the application the database may Depending on the application the database may

be organised so updating is quick or so that be organised so updating is quick or so that searching is quick.searching is quick.

Data may be indexed to allow speedy access.Data may be indexed to allow speedy access.

Security of AccessSecurity of AccessNeed to ensure that access to data is limited to Need to ensure that access to data is limited to

authorised users only.authorised users only.May have different access levels so users can May have different access levels so users can

search but not insert data etc.search but not insert data etc.

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Issues in Data ManagementIssues in Data Management

Concurrency: Concurrency: – Allowing multiple users to work on the database Allowing multiple users to work on the database

simultaneously.simultaneously.Not necessary in a single user system.Not necessary in a single user system.

TransactionsTransactions– Allowing multiple records to be changed Allowing multiple records to be changed

instantaneouslyinstantaneouslye.g. transfer of funds between two accounts.e.g. transfer of funds between two accounts.

– Need to ensure that if there is a problem during the Need to ensure that if there is a problem during the transaction the database reverts to the original state transaction the database reverts to the original state and that no one else can interfere with any of the and that no one else can interfere with any of the records during the transaction.records during the transaction.

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Issues in Data Management Issues in Data Management continuedcontinued

RecoveryRecovery– Surviving application and system crashes Surviving application and system crashes

Copying of data. Copying of data. – Ideally the database system should be able to import Ideally the database system should be able to import

data from other sources, and to export it for use data from other sources, and to export it for use elsewhere. elsewhere.

– Need some way to back up databases and to restore Need some way to back up databases and to restore in the event of a system failure that damages the in the event of a system failure that damages the database. database.

– hot backupshot backups is the term used when users can back up is the term used when users can back up databases while they are in use. databases while they are in use.

Needed for applications which must run without interruption, Needed for applications which must run without interruption, and cannot be shut down for backups. and cannot be shut down for backups.

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Defining the database structureDefining the database structure

The choice of DBMS will influence how the The choice of DBMS will influence how the data is organised.data is organised.

It is important when defining the database It is important when defining the database structure that the current and possible structure that the current and possible future needs of the organisation are taken future needs of the organisation are taken into account.into account.

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Centralised Data ManagementCentralised Data Management

Organisations may have data stored by different applications.– E.g. college may have student data in many different E.g. college may have student data in many different

locations.locations.

Problems can still arise if there is no single Problems can still arise if there is no single standard format for data.standard format for data.– Cannot integrate the data from different databases.Cannot integrate the data from different databases.

ExamplesExamples– Field names may be different.Field names may be different.– Field contents may be different.Field contents may be different.– Fields may be missing.Fields may be missing.

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Centralised Data ManagementCentralised Data Management

May be appropriate to have a single May be appropriate to have a single company wide data standard.company wide data standard.– However there can also be problems with this.However there can also be problems with this.

It can be very difficult to agree on the It can be very difficult to agree on the single standard.single standard.

Can lead to bureaucracy and lack of Can lead to bureaucracy and lack of flexibility.flexibility.

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ConclusionConclusion

Keeping data in databases is better than Keeping data in databases is better than keeping it in file systems.keeping it in file systems.

Data needs be managed.Data needs be managed.