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CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Specific Objective 4: explain the advantages of using a database approach compared to using
traditional file processing;
Content: Advantages including speed, efficiency, cost; data quality: completeness, validity,
consistency, timeliness and accuracy; data handling, data processing.
There are a number of characteristics that distinguish the database approach with the file-based
approach.
Self-Describing Nature of a Database System
A Database System contains not only the database itself but also the descriptions of data
structure and constraints (meta-data). This information is used by the DBMS software or
database users if needed. This separation makes a database system totally different from the
traditional file-based system in which the data definition is a part of application programs.
Insulation between Program and Data
In the file based system, the structure of the data files is defined in the application programs so if
a user wants to change the structure of a file, all the programs that access that file might need to
be changed as well. On the other hand, in the database approach, the data structure is stored in
the system catalog not in the programs. Therefore, one change is all that’s needed.
Support multiple views of data
A view is a subset of the database which is defined and dedicated for particular users of the
system. Multiple users in the system might have different views of the system. Each view might
contain only the data of interest to a user or a group of users.
Sharing of data and Multiuser system
A multiuser database system must allow multiple users access to the database at the same time.
As a result, the multiuser DBMS must have concurrency control strategies to ensure several
users access to the same data item at the same time, and to do so in a manner that the data will
always be correct – data integrity.
Control Data Redundancy
In the Database approach, ideally each data item is stored in only one place in the database. In
some cases redundancy still exists so as to improve system performance, but such redundancy is
controlled and kept to minimum.
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Data Sharing
The integration of the whole data in an organization leads to the ability to produce more
information from a given amount of data.
Enforcing Integrity Constraints
DBMSs should provide capabilities to define and enforce certain constraints such as data type,
data uniqueness, etc.
Restricting Unauthorised Access
Not all users of the system have the same accessing privileges. DBMSs should provide a
security subsystem to create and control the user accounts.
Data Independence
System data (Meta Data) descriptions are separated from the application programs. Changes to
the data structure is handled by the DBMS and not embedded in the program.
Transaction Processing
The DBMS must include concurrency control subsystems to ensure that several users trying to
update the same data do so in a controlled manner. The results of any updates to the database
must maintain consistency and validity.
Providing multiple views of data
A view may be a subset of the database. Various users may have different views of the database
itself. Users may not need to be aware of how and where the data they refer to is stored.
Providing backup and recovery facilities
If the computer system fails in the middle of a complex update process, the recovery subsystem
is responsible for making sure that the database is restored to the stage it was in before the
process started executing.
Managing information
Managing information means taking care of it so that it works for us, and is useful for the work
we are doing. The information we collect is no longer subject to “accidental disorganization” and
becomes more easily accessible and integrated with the rest of our work. Managing information
using a database allows us to become strategic users of the data we have.
We often need to access and re-sort data for various uses. These may include:

Creating mailing lists
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4

Writing management reports

Generating lists of selected news stories

Identifying various client needs
The processing power of a database allows it to manipulate the data it houses, so it can

Sort

Match

Link

Aggregate

Skip fields

Calculate

Arrange
So a database tracks data, finding the bits you need and processing them in the way you arrange
for them to be processed.
Because of the versatility of databases, we find them powering all sorts of projects. A database
can be linked to:

A web site that is capturing registered users

A client tracking application for social service organisations

A medical record system for a health care facility

Your personal address book in your e-mail client

A collection of word processed documents

A system that issues airline reservations
Source: http://bccampus.pressbooks.com/dbdesign/chapter/chapter-3-characteristics-andbenefits-of-a-database/, retrieved: August 26, 2013
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Comparison of Traditional File-Based Approach and Database Approach
At the beginning, you should understand the rationale of replacing the traditional file-based
system with the database system.
File-based System
File-based systems were an early attempt to computerize the manual filing system. File-based
system is a collection of application programs that perform services for the end-users. Each
program defines and manages its data.
However, five types of problem are occurred in using the file-based approach:
Separation and isolation of data
When data is isolated in separate files, it is more difficult for us to access data that should be
available. The application programmer is required to synchronize the processing of two or more
files to ensure the correct data is extracted.
Duplication of data
When employing the decentralized file-based approach, the uncontrolled duplication of data is
occurred. Uncontrolled duplication of data is undesirable because:
i. Duplication is wasteful
ii. Duplication can lead to loss of data integrity
Data dependence
Using file-based system, the physical structure and storage of the data files and records are
defined in the application program code. This characteristic is known as program-data
dependence. Making changes to an existing structure are rather difficult and will lead to a
modification of program. Such maintenance activities are time-consuming and subject to error.
Incompatible file formats
The structures of the file are dependent on the application programming language. However file
structure provided in one programming language such as direct file, indexed-sequential file
which is available in COBOL programming, may be different from the structure generated by
other programming language such as C. The direct incompatibility makes them difficult to
process jointly.
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Fixed queries / proliferation of application programs
File-based systems are very dependent upon the application programmer. Any required queries
or reports have to be written by the application programmer. Normally, a fixed format query or
report can only be entertained and no facility for ad-hoc queries if offered.
File-based systems also give tremendous pressure on data processing staff, with users'
complaints on programs that are inadequate or inefficient in meeting their demands.
Documentation may be limited and maintenance of the system is difficult. Provision for
security, integrity and recovery capability is very limited.
Database Approach
In order to overcome the limitations of the file-based approach, the concept of database and the
Database Management System (DMS) was emerged in 60s.
Advantages
A number of advantages of applying database approach in application system are obtained
including:
Control of data redundancy
The database approach attempts to eliminate the redundancy by integrating the file. Although
the database approach does not eliminate redundancy entirely, it controls the amount of
redundancy inherent in the database.
Data consistency
By eliminating or controlling redundancy, the database approach reduces the risk of
inconsistencies occurring. It ensures all copies of the idea are kept consistent.
More information from the same amount of data
With the integration of the operated data in the database approach, it may be possible to derive
additional information for the same data.
Sharing of data
Database belongs to the entire organization and can be shared by all authorized users.
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Improved data integrity
Database integrity provides the validity and consistency of stored data. Integrity is usually
expressed in terms of constraints, which are consistency rules that the database is not permitted
to violate.
Improved security
Database approach provides a protection of the data from the unauthorized users. It may take the
term of user names and passwords to identify user type and their access right in the operation
including retrieval, insertion, updating and deletion.
Enforcement of standards
The integration of the database enforces the necessary standards including data formats, naming
conventions, documentation standards, update procedures and access rules.
Economy of scale
Cost savings can be obtained by combining all organization's operational data into one database
with applications to work on one source of data.
Balance of conflicting requirements
By having a structural design in the database, the conflicts between users or departments can be
resolved. Decisions will be based on the base use of resources for the organization as a whole
rather that for an individual entity.
Improved data accessibility and responsiveness
By having an integration in the database approach, data accessing can be crossed departmental
boundaries. This feature provides more functionality and better services to the users.
Increased productivity
The database approach provides all the low-level file-handling routines. The provision of these
functions allows the programmer to concentrate more on the specific functionality required by
the users. The fourth-generation environment provided by the database can simplify the database
application development.
Improved maintenance
Database approach provides a data independence. As a change of data structure in the database
will be affect the application program, it simplifies database application maintenance.
Increased concurrency
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Database can manage concurrent data access effectively. It ensures no interference between
users that would not result any loss of information nor loss of integrity.
Improved backing and recovery services
Modern database management system provides facilities to minimize the amount of processing
that can be lost following a failure by using the transaction approach.
Disadvantages
In split of a large number of advantages can be found in the database approach, it is not without
any challenge. The following disadvantages can be found including:
Complexity
Database management system is an extremely complex piece of software. All parties must be
familiar with its functionality and take full advantage of it. Therefore, training for the
administrators, designers and users is required.
Size
The database management system consumes a substantial amount of main memory as well as a
large number amount of disk space in order to make it run efficiently.
Cost of DBMS
A multi-user database management system may be very expensive. Even after the installation,
there is a high recurrent annual maintenance cost on the software.
Cost of conversion
When moving from a file-base system to a database system, the company is required to have
additional expenses on hardware acquisition and training cost.
Performance
As the database approach is to cater for many applications rather than exclusively for a particular
one, some applications may not run as fast as before.
CAPE Information Technology
Unit 2
Module 1 Specific Objective 4
Higher impact of a failure
The database approach increases the vulnerability of the system due to the centralization. As all
users and applications reply on the database availability, the failure of any component can bring
operations to a halt and affect the services to the customer seriously.