DATA MANAGEMENT APPROACHES KEY ELEMENTS OF THE DATABASE

ENVIRONMENT
Flat-File Approach - Flat files are data files that contain
❖ Database Management System
records with no structured relationships to other files.
● Program development - to create applications
The flat-file approach is most often associated with
to access the database.
so-called legacy systems.
● Backup and recovery - DBMS can recover to an
The flat-file environment promotes a single-user view earlier version that is known to be correct
approach to data management whereby end users own ● Database usage reporting - captures statistics
their data files rather than share them with other users on what data are being used, when they are
used, and who uses them
Data redundancy - replication of essentially the same ● Database access - The most important feature
data in multiple files. It contributes to three significant of a DBMS is to permit authorized user access,
problems in the flat-file environment: data storage, data both formal and informal, to the database
updating, and currency of information
Data definition language (DDL) is a
Task-data dependency - user’s inability to obtain
programming language used to define the
additional information as his or her needs change
database to the DBMS. The DDL identifies the
Database Approach - This approach centralizes the names and the relationship of all data elements,
organization’s data into a common database that is records, and files that constitute the database.
shared by other users. With the enterprise’s data in a This definition has three levels, called views: the
central location, all users have access to the data they physical internal view, the conceptual view
need to achieve their respective objectives. Through (schema), and the user view (subschema).
data sharing, the traditional problems associated with
the flat-file approach may be overcome. Database Views
Internal View/Physical View. This is the lowest
● Elimination of Data Storage Problem - Each level of representation, which is one step
data element is stored only once, thereby removed from the physical database. This
eliminating data redundancy and reducing data internal view describes the structures of data
collection and storage costs records, the linkages between files, and the
● Elimination of Data Update Problem - Because physical arrangement and sequence of records
each data element exists in only one place, it in a file. There is only one internal view for the
requires only a single update procedure. This database.
reduces the time and cost of keeping the Database Views Internal View/Physical View.
database current. The physical arrangement of records in the
● Elimination of Currency Problem - A single database is presented through the internal view.
change to a database attribute is automatically This is the lowest level of representation, which
made available to all users of the attribute is one step removed from the physical database.
● Elimination of Task-Data Dependency Problem This internal view describes the structures of
- The most striking difference between the data records, the linkages between files, and the
database model and the flat-file model is the physical arrangement and sequence of records
pooling of data into a common database that is in a file. There is only one internal view or the
shared by all organizational users. With access database.
to the full domain of entity data, changes in External View/User View (Subschema). The
user information needs can be satisfied without subschema or user view, defines the user’s
obtaining additional private data sets. section of the database—the portion that an
individual user is authorized to access
 Data Attribute/Field - is a single item of data,
such as customer’s name, account balance, or
❖ Users
address.
Data manipulation Language (DML) is the Entity - is a database representation of an
proprietary programming language that a individual resource, event, or agent about which
particular DBMS uses to retrieve, process, and we choose to collect data.
store data. Entire user programs may be written Record Type (Table or File) - When we group
in the DML or, alternatively, selected DML together the data attributes that logically define
commands can be inserted into programs that an entity, they form a record type.
are written in universal languages, such as JAVA, Navigational Databases - The hierarchical data
C++, and even older languages such as COBOL model is called a navigational database because
and FORTRAN. traversing the files requires following a
predefined path.
A query is an ad hoc access methodology for The Network Model - Like the hierarchical
extracting information from a database. Users model, the network model is a navigational
can access data via direct query, which requires database with explicit linkages between records
no formal user programs using the DBMS’s and files. The distinction is that the network
built-in query facility. model permits a child record to have multiple
parents.
IBM’s Structured Query Language (SQL) - The Relational Model - The relational model
(often pronounced sequel or S-Q-L), has portrays data in the form of two-dimensional
emerged as the standard query language for tables
both mainframe and microcomputer DBMSs. Partitioned database approach - splits the
SQL is a fourth-generation, nonprocedural central database into segments or partitions
language (English-like commands) with many that are distributed to their primary user.
commands that allow users to input, retrieve, Deadlock - is a permanent condition that must
and modify data easily. be resolved by special software that analyzes
each deadlock condition to determine the best
Database administrator (DBA) - is responsible solution, can result in transactions being
for managing the database resource. The incompletely processed and the database being
sharing of a common database by multiple users corrupted.
requires organization, coordination, rules, and Resolving a deadlock - usually involves
guidelines to protect the integrity of the terminating one or more transactions to
database. complete processing of the other transactions in
the deadlock.
Data structures - are the bricks and mortar of Replicated databases - are effective in
the database. companies where there exists a high degree of
data sharing but no primary user.
Data Organization - of a file refers to the way Database concurrency - is the presence of
records are physically arranged on the complete and accurate data at all user sites.
secondary storage device, this may be either
sequential or random.
Data Access Methods - is the technique used to
CONTROLLING AND AUDITING DATA
locate records and to navigate through the
MANAGEMENT SYSTEMS
database.
Access controls are designed to prevent
unauthorized individuals from viewing,
 retrieving, corrupting, or destroying the entity’s and the database change log against the
data. database.
Backup controls ensure that in the event of data Recovery module uses the logs and backup files
loss due to unauthorized access, equipment to restart the system after a failure.
failure, or physical disaster the organization can
recover its database.
The user view or subschema is a subset of the
total database that defines the user’s data
domain and provides access to the database
Data base authorization table contains rules
that limit the actions a user can take
User-defined procedure allows the user to
create a personal security program or routine to
provide more positive user identification than a
single password

Audit Procedures for Testing Database Access

Controls
● Responsibility for Authority Tables and
Subschemas.
● Appropriate Access Authority
● Biometric Controls.
● Inference Controls.
● Encryption Controls.
● Backup Controls

Audit Procedures for Testing Flat-File Backup

Controls
● Sequential File (GPC) Backup - select a sample
of systems and determine from the system
documentation that the number of GPC backup
files specified for each system is adequate.
● Backup Transaction Files - verify through
physical observation that transaction files used
to reconstruct the master files are also retained
● Direct Access File Backup - should select a
sample of applications and identify the direct
access files being updated in each system
● Off-Site Storage - verify the existence and
adequacy of off-site storage.

Transaction log feature provides an audit trail

of all processed transactions.
Checkpoint facility suspends all data processing
while the system reconciles the transaction log