Database Planning, Design, and Administration: © Pearson Education Limited 1995, 2005

Chapter 9
Database Planning, Design,

and Administration
© Pearson Education Limited 1995, 2005

Chapter 9 - Objectives
 Main components of an information system.
 Main stages of database system development

lifecycle.
 Main phases of database design: conceptual,

logical, and physical design.
 Benefits of CASE tools.
2
Chapter 9 - Objectives
 How to evaluate and select a DBMS.
 Distinction between data administration and

database administration.
 Purpose and tasks associated with data

administration and database administration.
32
Software Depression
 Last few decades have seen proliferation

of software applications, many requiring
constant maintenance involving:
– correcting faults,
– implementing new user requirements,
– modifying software to run on new or upgraded
platforms.
 Effortspent on maintenance began to absorb
resources at an alarming rate.
4
Software Depression
 As a result, many major software projects were
– late,
– over budget,
– unreliable,
– difficult to maintain,
– performed poorly.
 In late 1960s, led to ‘software crisis’, now refer
to as the ‘software depression’.
5
Software Depression
 Major reasons for failure of software projects
includes:
- lack of a complete requirements specification;
- lack of appropriate development methodology;
- poor decomposition of design into manageable
components.
 Structured approach to development was
proposed called Information Systems Lifecycle
(ISLC).
6
Information System
Resources that enable collection, management,
control, and dissemination of information
throughout an organization.
 Database is fundamental component of IS, and

its development/usage should be viewed from
perspective of the wider requirements of the
organization.
7
Database System Development Lifecycle
 Database planning
 System definition
 Requirements collection and analysis
 Database design
 DBMS selection (optional)
8
Database System Development Lifecycle
 Application design
 Prototyping (optional)
 Implementation
 Data conversion and loading

 Testing
 Operational maintenance
9
Stages of the Database System Development
Lifecycle
10
Database Planning
 Management activities that allow stages of
database system development lifecycle to be
realized as efficiently and effectively as
possible.
 Must be integrated with overall IS strategy of

the organization.
11
Database Planning – Mission Statement
 Mission statement for the database project
defines major aims of database application.
 Those driving database project normally define

the mission statement.
 Mission statement helps clarify purpose of the
database project and provides clearer path
towards the efficient and effective creation of
required database system.
12
Database Planning – Mission Objectives
 Once mission statement is defined, mission
objectives are defined.
 Each objective should identify a particular task

that the database must support.
 May be accompanied by some additional
information that specifies the work to be done,
the resources with which to do it, and the
money to pay for it all.
13
Database Planning
 Database planning should also include
development of standards that govern:
– how data will be collected,
– how the format should be specified,
– what necessary documentation will be needed,
– how design and implementation should proceed.
14
System Definition
 Describesscope and boundaries of database

system and the major user views.
 User view defines what is required of a

database system from perspective of:
– a particular job role (such as Manager or
Supervisor) or
– enterprise application area (such as
marketing, personnel, or stock control).
15
System Definition
 Database application may have one or more
user views.
 Identifyinguser views helps ensure that no

major users of the database are forgotten when
developing requirements for new system.
 User views also help in development of complex

database system allowing requirements to be
broken down into manageable pieces.
16
Representation of a Database System with
Multiple User Views
17

Requirements Collection and Analysis
 Process of collecting and analyzing information
about the part of organization to be supported
by the database system, and using this
information to identify users’ requirements of
new system.
18
 Information is gathered for each major user view
including:
– a description of data used or generated;
– details of how data is to be used/generated;
– any additional requirements for new database
system.
 Information is analyzed to identify requirements
to be included in new database system. Described
in the requirements specification.
19
 Another important activity is deciding how to

manage the requirements for a database
system with multiple user views.
 Three main approaches:
– centralized approach;
– view integration approach;
– combination of both approaches.
20
 Centralized approach
– Requirements for each user view are merged
into a single set of requirements.
– A data model is created representing all user
views during the database design stage.
21
Centralized Approach to Managing
Multiple User Views
22
 View integration approach
– Requirements for each user view remain as
separate lists.
– Data models representing each user view are
created and then merged later during the
database design stage.
23
 Data model representing single user view (or a

subset of all user views) is called a local data
model.
 Each model includes diagrams and

documentation describing requirements for one
or more but not all user views of database.
24
 Local data models are then merged at a later

stage during database design to produce a global
data model, which represents all user views for
the database.
25
View Integration Approach to Managing
Multiple User Views
26
© Pearson Education Limited
1995, 2005
Database Design
 Process of creating a design for a database that
will support the enterprise’s mission statement
and mission objectives for the required
database system.
27
Database Design
 Main approaches include:
– Top-down
– Bottom-up
– Inside-out
– Mixed
28
Database Design
 Main purposes of data modeling include:
– to assist in understanding the meaning
(semantics) of the data;
– to facilitate communication about the
information requirements.
 Building data model requires answering

questions about entities, relationships, and
attributes.
29
Database Design
 A data model ensures we understand:
- each user’s perspective of the data;
- nature of the data itself, independent of its
physical representations;
- use of data across user views.
30
Criteria to Produce an Optimal Data Model
31
Database Design
 Three phases of database design:
– Conceptual database design

– Logical database design
– Physical database design.
32
Conceptual Database Design
 Process of constructing a model of the data

used in an enterprise, independent of all
physical considerations.
 Data model is built using the information in

users’ requirements specification.
 Conceptual data model is source of

information for logical design phase.
33
Logical Database Design
 Process of constructing a model of the data
used in an enterprise based on a specific data
model (e.g. relational), but independent of a
particular DBMS and other physical
considerations.
 Conceptual data model is refined and mapped

on to a logical data model.
34
Physical Database Design
 Processof producing a description of the

database implementation on secondary storage.
 Describes base relations, file organizations, and

indexes used to achieve efficient access to data.
Also describes any associated integrity
constraints and secuirty measures.
 Tailored to a specific DBMS system.
35
Three-Level ANSI-SPARC Architecture
and Phases of Database Design
36
DBMS Selection
 Selectionof an appropriate DBMS to support
the database system.
 Undertaken at any time prior to logical design
provided sufficient information is available
regarding system requirements.
 Main steps to selecting a DBMS:
– define Terms of Reference of study;
– shortlist two or three products;
– evaluate products;
– recommend selection and produce report.
37
DBMS Evaluation Features
38
DBMS Evaluation Features
39
Example - Evaluation of DBMS Product
40
Application Design
 Design of user interface and application
programs that use and process the database.
 Database design and application design are

parallel activities.
 Includes two important activities:

– transaction design;
– user interface design.
41
Application Design - Transactions
 An action, or series of actions, carried out by a
single user or application program, which
accesses or changes content of the database.
 Should define and document the high-level

characteristics of the transactions required.
42
Application Design - Transactions
 Important characteristics of transactions:
– data to be used by the transaction;
– functional characteristics of the transaction;
– output of the transaction;
– importance to the users;
– expected rate of usage.
 Three main types of transactions: retrieval,
update, and mixed.
43
Prototyping
 Building working model of a database system.
 Purpose
– to identify features of a system that work well,
or are inadequate;
– to suggest improvements or even new features;
– to clarify the users’ requirements;
– to evaluate feasibility of a particular system
design.
44
Implementation
 Physical realization of the database and application
designs.
– Use DDL to create database schemas and empty
database files.
– Use DDL to create any specified user views.
– Use 3GL or 4GL to create the application
programs. This will include the database
transactions implemented using the DML,
possibly embedded in a host programming
language.
45
Data Conversion and Loading
 Transferring any existing data into new database
and converting any existing applications to run on
new database.
 Only required when new database system is

replacing an old system.
– DBMS normally has utility that loads existing
files into new database.
 May be possible to convert and use application
programs from old system for use by new system.
46
Testing
 Process of running the database system with intent
of finding errors.
 Use carefully planned test strategies and realistic

data.
 Testing cannot show absence of faults; it can show
only that software faults are present.
 Demonstrates that database and application
programs appear to be working according to
requirements.
47
Testing
 Should also test usability of system.
 Evaluation conducted against a usability
specification.
 Examples of criteria include:

– Learnability;
– Performance;
– Robustness;
– Recoverability;
– Adaptability.
48
Operational Maintenance
 Processof monitoring and maintaining
database system following installation.
 Monitoring performance of system.
– if performance falls, may require tuning or
reorganization of the database.
 Maintaining and upgrading database
application (when required).
 Incorporating new requirements into database
application.
49
CASE Tools
 Support provided by CASE tools include:

- data dictionary to store information about
database system’s data;
- design tools to support data analysis;
- tools to permit development of corporate
data model, and conceptual and logical data
models;
- tools to enable prototyping of applications.
50
CASE Tools
 Provide following benefits:
– Standards;
– Integration;
– Support for standard methods;
– Consistency;
– Automation .
51
CASE Tools and Database System
Development Lifecycle
52
Data Administration and Database
Administration
 The Data Administrator (DA) and Database
Administrator (DBA) are responsible for
managing and controlling the corporate data
and corporate database, respectively.
 DA is more concerned with early stages of

database system development lifecycle and
DBA is more concerned with later stages.
53
Data Administration
 Management of data resource including:

– database planning,
– development and maintenance of standards,
policies and procedures, and conceptual and
logical database design.
54
Data Administration
 Management of data resource including:

– database planning,
– development and maintenance of standards,
policies and procedures, and conceptual and
logical database design.
55
Database Administration
 Management of physical realization of a

database system including:
– physical database design and
implementation,
– setting security and integrity controls,
– monitoring system performance, and
reorganizing the database.
56

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Chapter 9

Database Planning, Design,

© Pearson Education Limited 1995, 2005

 Main stages of database system development

 Main phases of database design: conceptual,

 Benefits of CASE tools.

 Distinction between data administration and

 Purpose and tasks associated with data

 Last few decades have seen proliferation

 Database is fundamental component of IS, and

 Requirements collection and analysis

 DBMS selection (optional)

 Data conversion and loading

 Must be integrated with overall IS strategy of

 Those driving database project normally define

 Each objective should identify a particular task

 Describesscope and boundaries of database

 User view defines what is required of a

 Identifyinguser views helps ensure that no

 User views also help in development of complex

© Pearson Education Limited 1995, 2005

 Another important activity is deciding how to

 Data model representing single user view (or a

 Each model includes diagrams and

 Local data models are then merged at a later

 Building data model requires answering

 Three phases of database design:

– Conceptual database design

 Process of constructing a model of the data

 Data model is built using the information in

 Conceptual data model is source of

 Conceptual data model is refined and mapped

 Processof producing a description of the

 Describes base relations, file organizations, and

 Tailored to a specific DBMS system.

 Database design and application design are

 Includes two important activities:

 Should define and document the high-level

 Only required when new database system is

 Use carefully planned test strategies and realistic

 Examples of criteria include:

 Support provided by CASE tools include:

 DA is more concerned with early stages of

 Management of data resource including:

 Management of data resource including:

 Management of physical realization of a

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