ITC114

ITC114ITC114

Database Database AdministratiAdministrati

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April 8, 2023 ITC114 Page 2

ObjectivesObjectives

At the completion of this lecture you should be able to :

Describe and contrast the technical & managerial roles of the Database Administrator.

Explain the role of the data dictionary. Outline the role of CASE tool in

management of a database. Describe the requirements for the

successful implementation of a data administration strategy.


Database AdministrationDatabase Administration

Data is a corporate asset.

Data is a resource to be translated into information.

To maximise on the value of data, managers must understand the value of information (processed data)

The responsibility for supervising both the database and the use of the DBMS resides with the database administration.

Data-Information Decision CycleData-Information Decision Cycle

Knowledge

Information

Actions

Decision makingUser

Data

interprets

used in

that is the basis of

converted

triggers

generatesmore

analysis


What does a DBMS do?What does a DBMS do?

• ensures data is processed according to requirements – integrity constraints.

• distributes data & information in a timely manner.

• ensures the security of the data.• Maintains data independence – allows changes

in the structure of the database without the applications being affected.

• supports managerial decision making at all levels.

• Allows for the replication of data at different locations.

• Provide facilities to recover the database in the even of damage to the database.

Managerial Decision Making LevelsManagerial Decision Making Levels

Operational managemt

Middle managemt

Topmanagemt

DBMS

Database

Database’s predominant role to support managerial decision making at all levels.


A DBMS is a tool to manage data.A DBMS is a tool to manage data.

DBMS must be properly managed from:Technological side

involves selecting, installing, configuring & monitoring of DBMS. Requires approximately technical skills.

Managerial side DBMS does not guarantee a good information

system, it still requires good management and organisational support.

Cultural side can create resistance as involves change. e.g.

data ownership will be shared, value, accuracy, security, privacy all issues.


Role of DBA versus Data AdministratorRole of DBA versus Data Administrator

Data AdministratorResponsible for developing the enterprise data model plus the maintenance of data definitions and standards.

Database Administrator (DBA): A technical and managerial function responsible for all aspects of the physical database analysis and design plus including such as its performance, the security, and backup and recovery.


More on the data administratorMore on the data administrator

Data Administrator (DA) provides a global view of the organisation’s data (manual & computerised). The role could be consumed by the DBA but it typically is a lower managerial level compared to the DBA.

Responsibilities include issues of:

determine the data requirements of the organisation.

data consistency & integrity. highlighting data as a corporate resource.


Career path to be a DBACareer path to be a DBA

Programmer Analyst

Programmer

ProjectLeader / DA

Database Administrator


Role of Database Administrator (DBA)Role of Database Administrator (DBA)

Database Administrator • is a both a technical and a management function

responsible for the physical database support.• The DBA is charged with all aspects of a DBMS,

including selection and management.• basically responsible for supervising the

database and the use of the DBMS.

Responsibilities & skills can be broken into

managerial.

technical.


Management qualities of a DBAManagement qualities of a DBA

ability to be able to effectively liaise with end-users.

be able to develop policies and procedures (standards).

Skills in: planning analysis, design, implementation, testing

procedures data security, privacy and integrity. backup & disaster recovery procedures.

The qualities of the DBA lie between the technical and the managerial activities


Technical Role of the DBATechnical Role of the DBA

Generic Skills ………

Specific tasks of the DBA in selecting DBMS:– choose the DBMS model.– storage capacity, add-on support, security and

integrity, backup-recovery, concurrency controls, performance, database admin support, H/W requirements, cost, training support.

– data loading, conversion, access plan.– affording access rights to users.


Access privileges and securityAccess privileges and security

Access– Users should access the database

only in ways in which they are entitled.

– Defined by the DBASecurity Protection of data against accidental or

intentional loss, destruction or misuse. Can include:– Human error– Software failure– Hardware failure


Security issues ….Security issues ….

Theft of InformationImproper data access

– Privacy issues– Confidentiality

Unauthorised modification of data

Unauthorised destruction of data


What are some of the security issues …What are some of the security issues …Authorisation

– Access restrictions ensure that the database is secure.

– Effective password protection is critical however ….

• Can be shared

• Can be written down and copied

• Automatically login can be employed

• Unencrypted passwords can be intercepted.

Alternatives– Biometrics – Digital certificates



Other duties of the database administratorOther duties of the database administrator

– enforcement of standards – programming, naming conventions, testing procedures, H/W upgrade standards, change control …..

– maintaining the data dictionary– provide assistance and support during the

conceptual, logical and physical design.– database design support.– testing and evaluation of the database.

training


The database administrator can use a checklist to assist in the selection and the evaluation of the DBMS


The DBA can evaluate the purchase of a DBMS in terms of the categories lists in this figure.


and yes …. there is more ….


Database Administration StrategyDatabase Administration Strategy

• depends on the organisation.

• can be referred to by different names.

• need to link it to the corporate strategy.

• it is a framework of management/ support for organisations data (asset).


Planning for a disaster …Planning for a disaster …

A DBA must plan for disasters:• Intentional – unauthorised access• Accidental – disk problem, power outage, computer

malfunction, flood or some other natural disaster

DBA must take an active role in a disaster recovery plan

So how do you plan for a disaster?• you must know the value of your data ….• for what period can your organisation

function without access to the data?• The DBA must be proactive in developing

a disaster recovery plan.


Disaster Recovery PlanDisaster Recovery Plan

• Typically a journal or a file will be accessed to obtain information about the state of the database just before the disaster.

• PC-based DBMS machines lack facilities to maintain an effective journal limited recovery is possible.

• Alternative is to add additional DBMS features to support the database


A journal records changes made to the database – basically creates an audit trail

To recover the database the back copy is recovered first, and then the journal is used to simulate changes since the last backup.

How does the journal operate?


What is the purpose of an archive?What is the purpose of an archive?

Archiving is the process of ‘off-loading’ documents and records to an alternate disk space.


Backup facilitiesBackup facilities

• Ensure automatic dump of the database

• Periodic – nightly, weekly, monthly

• Backup – completed at specific time – may require shut down of the part/whole system.


So what happens if the database fails ….So what happens if the database fails ….

1. Aborts transaction – typically rollback

2. Incorrect data – rollback

3. System failure – prefer approach – use redundant system

4. Database destruction – again switch to redundant system – otherwise roll forward


Where does the position of DBA fit?Where does the position of DBA fit?

initially was a functional responsibility.

depends on the organisation.

Should be a very high managerial position.

Resources of the DBAResources of the DBA

Data Dictionary

Case tools

Project Management tools

Decision Support Systems


1.The Data Dictionary- stores the definitions and relationships of the DBMS.

Classified by: stand-alone or integrated.

active or passive.


Data DictionaryData Dictionary

A data dictionary is a comprehensive document that defines the everything about a system.

A DD not only includes the actual data but also metadata - data about the database e.g.

– table definitions– indexes– who created the database– valid users– valid applications that can access the DBMS– Authorisations / security


More on the data dictionaryMore on the data dictionary

• no standard to a DD but the more it supports the DBMS the better.

• Some authors may refer to it as a Project Dictionary

• you must be able to access the data dictionary in the same way as you would the actual data - therefore can use SQL e.g.SELECT NAME, CTIME

FROM SYSTABLESWHERE CREATOR = “ATKINSON”


2. CASE tools(Computer Aided Software

Engineering)

Can be classified as: Front-end CASE tools (support for

planning, analysis & design) .

Back-end CASE tools (support for coding & implementation).


Functions of a CASE toolFunctions of a CASE tool

• Graphics – in particular model drawing facilities

• Screen designers and report generators• An integrated repository (DD)• An analysis component to provide an

automated check on system consistency, syntax and completeness

• A program documentation generator.

Central to a CASE tool is the central repository, basically the DD, to integrate all the data.



3. Project Management resources / skillsBasically requires the DBA to coordinate, direct, control and manage the timing of any project work. Software to do this can include – MS Project– GANNT Charts– PERT chart– ITC301



4. Decision Support SystemsDSS is software the DBA to help make the decision maker make decisions.

- Alternatively it could be Executive Information Systems (EIS)- Assisted through use of data

warehousing technology

ITC114

Documents

decision support systems

end case tools

disaster recovery plan

case tools

case tool

actual data

organisations data

data administrator