Database Resource Management
Database Resource Management
Database Resource Management
Anatoly Sachenko
I. LECTURE OVERVIEW
Foundation Concepts: Foundations of Information in Business presents an overview of the five basic areas of
information systems knowledge needed by business professionals, including the conceptual system components and
major types of information systems.
Data Resource Management – Data resource management is a managerial activity that applies information
systems technology and management tools to the task of managing an organization’s data resources. It includes
the database administration function that focuses on developing and maintaining standards and controls for an
organization’s databases. Data administration, however, focuses on the planning and control of data to support
business functions and strategic organizational objectives. This includes a data planning effort that focuses on
developing an overall data architecture for a firm’s data resources.
Database Management - The database management approach affects the storage and processing of data. The data
needed by different applications are consolidated and integrated into several common databases, instead of being
stored in many independent data files. Also, the database management approach emphasizes updating and
maintaining common databases, having users’ application programs share the data in the database, and providing a
reporting and an inquiry/response capability so end users can easily receive reports and quick responses to requests
for information.
Database Software - Database management systems are software packages that simplify the criterion, use, and
maintenance of databases. They provide software tools so end users, programmers, and database administrators can
create and modify databases, interrogate a database, generate reports, do application development, and perform
database maintenance.
Types of Databases - Several types of databases are used by business organizations, including operational,
distributed, and external databases. Data warehouses are a central source of data from other databases that have
been cleaned, transformed and cataloged for business analysis and decision support applications. That includes
data mining, which attempts to find hidden patterns and trends in the warehouse data. Hypermedia databases on
the World Wide Web and corporate intranets and extranets store hyperlinked multimedia pages at a website. Web
server software can manage such databases for quick access and maintenance of the Web database.
Database Development - The development of databases can be easily accomplished using microcomputer database
management packages for small end user applications. However, the development of large corporate databases
requires a top-down data planning effort. This may involve developing enterprise and entity relationship models,
subject area databases, and data models that reflect the logical data elements and relationships needed to support
the operation and management of the basic business processes of the organization.
Data Access - Data must be organized in some logical manner on physical storage devices so that they can be
efficiently processed. For this reason, data are commonly organized into logical data elements such as characters,
fields, records, files, and databases. Database and object-oriented models, are used to organize the relationships
among the data records stored in databases. Databases and files can be organized in either a sequential or direct
manner and can be accessed and maintained by either sequential access or direct access processing methods.
Data is a vital organizational resource, which needs to be managed like other important business assets. Most
organizations could not survive or succeed without quality data about their internal operations and external
environment. Managers need to practice data resource management - a managerial activity that applies
information systems technology like database management and other management tools to the task of managing an
organization's data resources to meet the information needs of business users.
A hierarchy of several levels of data has been devised that differentiates between different groupings, or elements,
of data. Data are logically organized into:
• Character - A character is the most basic logical data element. It consists of a single alphabetic, numeric, or
other symbol.
• Field - A field consists of a grouping of characters. A data field represents an attribute (a characteristic or
quality) of some entity (object, person, place, or event).
• Record - Related fields of data are grouped to form a record. Thus, a record represents a collection of
attributes that describe an entity. Fixed-length records contain a fixed number of fixed-length data fields.
Variable-length records contain a variable number of fields and field lengths.
• File - A group of related records is known as a data file, or table. Files are frequently classified by the
application for which they are primarily used, such as a payroll file or an inventory file, or the type of data
they contain, such as a document file or a graphical image file. Files are also classified by their permanence,
for example, a master file versus a transaction file. A transaction file would contain records of all transactions
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occurring during a period, whereas a master file contains all the permanent records. A history file is an
obsolete transaction or master file retained for backup purposes or for long-term historical storage called
archival storage.
• Database - A database is an integrated collection of logically related records or objects. A database
consolidates records previously stored in separate files into a common pool of data records that provides data
for many applications. The data stored in a database is independent of the application programs using it and
of the type of secondary storage devices on which it is stored.
Continuing developments in information technology and its business applications have resulted in the evolution of
several major types of databases. Several major conceptual categories of databases that may be found in computer-
using organizations include:
• Operational Databases - These databases store detailed data needed to support the operations of the entire
organization. They are also called subject area databases (SADB), transaction databases, and production
databases. Examples are customer databases, personnel databases, inventory databases, and other databases
containing data generated by business operations.
• Distributed Databases - Many organizations replicate and distribute copies or parts of databases to network
servers at a variety of sites. These distributed databases can reside on network servers on the World Wide Web,
on corporate Intranets or extranets, or on other company networks. Distributed databases may be copies of
operational or analytical databases, hypermedia or discussion databases, or any other type of database.
Replication and distribution of databases is done to improve database performance and security.
• External Databases - Access to external, privately owned online databases or data banks is available for a fee
to end users and organizations from commercial online services, and with or without charge from many
sources on the Internet, especially the Web.
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• Hypermedia Databases on the Web: [Figure 3.6] - The rapid growth of web sites on the Internet and
corporate Intranets and extranets has dramatically increased the use of databases of hypertext and hypermedia
documents. A web site stores such information in a hypermedia database consisting of a home page and other
hyperlinked pages of multimedia or mixed media (text, sound, etc.).
• Data Warehouses - A data warehouse stores data from current and previous years that has been extracted from
the various operational and management databases of an organization. It becomes a central source of data,
which has been screened, edited, standardized, and integrated so it can be used by managers and other end
user professionals throughout an organization. Data warehouses may be subdivided into data marts, which
hold specific subsets of data from the warehouse.
• Data Mining - A major use of data warehouse databases is data mining. In data mining, the data in a data
warehouse are processed to identify key factors and trends in historical patterns of business activity that can be
used to help managers make decisions about strategic changes in business operations to gain competitive
advantages in the marketplace.
The development of databases and database management software is the foundation of modern methods of
managing organizational data.
• Database Management Approach - Is a method whereby data records and objects are consolidated into
databases that can be accessed by many different application programs.
• Database Management System - (DBMS) serves as a software interface between users and databases. Thus,
database management involves the use of database management software to control how databases are created,
interrogated, and maintained to provide information needed by end users and their organizations.
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The database management approach involves three basic activities:
• Updating and maintaining common databases to reflect new business transactions and other events requiring
changes to an organization’s records.
• Providing information needed for each end user’s application by using application programs that share the
data in common databases.
• Providing an inquiry/response and reporting capability through a DBMS package so that end users can easily
interrogate databases, generate reports, and receive quick responses to their ad hoc requests for information.
A database management system (DBMS) is a set of computer programs that controls the creation, maintenance,
and use of the databases of an organization and its end users. The four major uses of a DBMS include:
• Database Development
• Database Interrogation
• Database Maintenance
• Application Development
Database Interrogation:
The database interrogation capability is a major benefit of a database management system. End users can use a
DBMS by asking for information from a database using a query language or a report generator.
SQL, or Structured Query Language, is a query language found in many database management packages. It is
used to obtaining immediate responses to ad hoc inquiries.
SELECT........... FROM.............WHERE
QBE, or Query by Example, is another form of query language found in some database management packages.
The QBE method displays boxes for each of the data fields in one or more files. The end user simply “points-and-
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clicks” to indicate which information they want.
Graphical and Natural Queries - Most end user database management packages offer GUI (graphical user
interface) point-and-click methods to query a database. These methods are easy to use and are translated by the
software into SQL commands. Other packages are available that use natural language query statements similar to
conversational English.
Application Development:
DBMS packages play a major role in application development. Application development is made easier by data
manipulation language (DML) statements, which can be included in application programs to let the DBMS
perform the necessary data handling activities. Programmers can also use the internal programming language
provided by many DBMS packages or a built-in application generator to develop complex application programs.
Managerial end users should view data as an important resource that they must learn to manage properly to ensure
the success and survival of their organizations. Database management is an important application of information
systems technology to the management of a firm’s data resources. Data resource management includes:
• Database Administration: - Is an important data resource management function responsible for the proper use
of database management technology. Database administration has more operational and technical
responsibilities than other data resource management functions. This includes responsibility for:
- Developing and maintaining the organization’s data dictionary
- Designing and monitoring the performance of databases
- Enforcing standards for use and security.
• Data Planning: - Data planning is a corporate planning and analysis function that focuses on data resource
management. It includes the responsibility for:
- Developing an overall data architecture for the firm’s data resources that ties in with the firm’s strategic
mission and plans, and the objectives and processes of its business units.
- Data planning is a major component of an organization’s strategic planning process. It is done by
organizations that have made a formal commitment to long-range planning for the strategic use and
management of its data resources.
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• Data Administration: - Is another data resource management function. It involves the:
- Establishment and enforcement of policies and procedures for managing data as a strategic corporate
resource.
- Collection, storage, and dissemination of all types of data are administrated in such a way that data become a
standardized resource available to all end users in the organization.
- The planning and control of data in support of an organization’s business functions and strategic business
objectives.
- Establishment of a data planning activity for the organization.
- Developing policies and set standards for corporate database design, processing, and security arrangements,
and to select database management and data dictionary software.
Challenges of Data Resource Management:
The database resource management approach provides business managers and professionals with several important
benefits such as:
• Reduce the duplication of data
• Integrate data so that multiple programs and users can access them.
• Programs are not dependent on the format of the data and the type of secondary storage hardware being used.
• Users are provided with an inquiry/response and reporting capability that allows them to easily obtain
information they need without having to write computer programs.
• Computer programming is simplified, because programs are not dependent on either the logical format of the
data or their physical storage location.
• Integrity and security of the data stored in databases can be increased, since database management system
software, a data dictionary, and a database administrator function control access to data and modification of
the database.
In all information systems, data resources must be organized and structured in some logical manner so that they
can be accessed easily, processed efficiently, retrieved quickly, and managed effectively. Data structures and access
methods ranging from simple to complex have been devised to effectively organize and access data stored by
information systems.
The relationships among the many individual records in databases are based on one of several logical data
structures or models. DBMS are designed to provide end users with quick, easy access to information stored in
databases. Five fundamental database structures are:
• Hierarchical Structure:
Early mainframe DBMS packages used the hierarchical structure, in which:
- Relationships between records form a hierarchy or treelike structure.
- Records are dependent and arranged in multilevel structures, consisting of one root record and any number of
subordinate levels.
- Relationships among the records are one-to-many, since each data element is related only to one element
above it.
- Data element or record at the highest level of the hierarchy is called the root element. Moving progressively
downward from the root and along the branches of the tree until the desired record is located can access any
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data element.
• Network Structure:
The network structure:
- Can represent more complex logical relationships, and is still used by many mainframe DBMS packages.
- Allows many-to-many relationships among records. That is, the network model can access a data element by
following one of several paths, because any data element or record can be related to any number of other data
elements.
• Relational Structure:
The relational structure:
- Most popular of the three database structures.
- Used by most microcomputer DBMS packages, as well as many minicomputer and mainframe systems.
- Data elements within the database are stored in the form of simple tables. Tables are related if they contain
common fields.
- DBMS packages based on the relational model can link data elements from various tables to provide
information to users.
• Object-Oriented Structure
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The object-oriented structure:
- Is considered to be one of the key technologies of a new generation of multimedia web-based applications.
- In an object-oriented structure, an object consists of data values describing the attributes of an entity plus the
operations that can be performed upon the data. This encapsulation capability allows the object-oriented
model to better handle more complex types of data (graphics, voice, text) than other database structures.
- Supports inheritance, that is, new objects can be automatically created by replicating some or all of the
characteristics of one or more parent objects.
-Object capabilities and inheritance have made object-oriented database management systems (OODBMS)
popular in computer-aided design (CAD) applications. Designers can develop product designs, store them as
objects in an object-oriented database, and replicate and modify them to create new product designs.
Multimedia web-based applications for the Internet and corporate Intranets and extranets have become a major
application area for object technology.
Object-oriented database software is finding increased use in managing the hypermedia databases and Java applets
on the World Wide Web and corporate Intranets and extranets. Industry proponents predict that object-oriented
database management systems (OODBMS) will become the key software component that manages the hyperlinked
multimedia pages and other types of data that support corporate web sites.
Hierarchical Data Ease with which data can be Hierarchical one-to-many relationships must
Structure stored and retrieved in be specified in advance, and are not flexible.
structured, routine types of
transactions. Cannot easily handle ad hoc requests for
information.
Ease with which data can be
extracted for reporting purposes. Modifying a hierarchical database structure is
complex.
Structured and routine types of
transaction processing are fast Great deal of redundancy.
and efficient.
Requires knowledge of a programming
language.
Network Structure More flexible that the Network many-to-many relationships must be
hierarchical model. specified in advance.
Multidimensional Compact and easy to understand Not currently developed for broad business
Structure way to visualize and manipulate application use.
data elements that has many
interrelationships.
Relational Structure Flexible in that it can handle ad Cannot process large amounts of business
hoc information requests. transactions as quickly and efficiently as the
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hierarchical and network models.
Easy for programmers to work
with. End users can use this
model with little effort or
training.
Object-Oriented Structure Handles complex types of data Not currently developed for broad business
(graphics, pictures, voice, and use.
text) better than other structures.
ACCESSING DATABASES
Databases and data files are stored on various types of storage media and are organized in a variety of ways to
make it easier to access the data records they contain. In database maintenance, records or objects have to be
continually added, deleted, or updated to reflect business transactions, and they also need to be accessed so
information can be produced in response to end user requests.
Key Fields
Records usually contain one or more identification fields, or keys that identify the record, so that it can be located.
Other methods also identify and link data records stored in several different database files. Hierarchical and
network databases may use pointer fields. These are fields within a record that indicate (point to) the location of
another record that is related to it in the same file, or in another file. Hierarchical and network database
management systems use this method to link records so they can retrieve information from several different
database files.
Relational database management packages use primary keys to link records. Each table (file) in a relational
database must contain a primary key. This field uniquely identifies each record in a file and must also be found in
other related files.
Sequential Access:
One of the basic ways to access data is sequential access. This method uses a sequential organization, in which
records are physically stored in a specified order according to a key field in each record.
Direct Access:
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When using direct access methods, records do not have to be arranged in any particular sequence on storage
media. Characteristics of the direct access method:
• Computers must keep track of the storage location of each record using a variety of direct organization
methods so that data can be retrieved when needed.
• New transactions’ data do not have to be sorted.
• Processing that requires immediate responses or updating is easily handled.
Three common ways to directly access records in the direct organization method include:
• Key Transformation: - This method performs an arithmetic computation on a key field or record and uses the
number that results from that calculation as an address to store and access that record.
• Index: - This method uses an index of record keys and related storage addresses. A new data record is stored
at the next available location, and its key and address are placed in an index. The computer uses this index,
whenever it must access a record.
• Indexed Sequential Access Method (ISAM): - In this method records are physically stored in sequential order
on a magnetic disk or other direct access storage device based on the key field of each record. Each file
contains an index that references one or more key fields of each data record to its storage location address.
DATABASE DEVELOPMENT
Developing small personal databases is relatively easy using microcomputer DBMS packages. However,
developing a large database can be a complex task. In many companies, developing and managing corporate
databases is the primary responsibility of the database administrator and database design analysts. They work with
end users and systems analysts to determine:
• What data definitions should be included in the database
• What structure or relationships should exist among the data elements.
Database development must start with a top-down data planning process. Database administrators work with
corporate and end user management according to the following steps:
• Develop an enterprise model to define the basic business processes of the enterprise.
• Define the information needs of end users in a business process.
• Identify the key data elements that are needed to perform their specific business activities.
• Develop entity relationship diagrams (ERDs) that model the relationships among the many entities involved in
the business process.
The user views become the basis for the data modelling steps where the relationships between data elements are
identified. Each data model defines the logical relationships among the data elements needed to support a basic
business process. These data models then serve as logical frameworks (schemas and subschemas) on which to base
the physical design of databases and the development of application programs to support the business processes of
the organization.
• Data Models - Represent a logical view of the data and relationships of the data.
• Schema - Is an overall logical view of the relationships between data in a database.
• Subschema - Is a logical view of data relationships needed to support specific end user application programs
that will access that database.
• Physical or Internal View - Looks at how data is physically arranged, stored, and accessed on the
magnetic disks and other secondary storage devices of a computer system.
Data Mining:
A process where data in a data warehouse is identified to discover key business trends and factors.
Data Modeling:
A process where the relationships between data elements are identified and defined to develop data models.
Data Planning:
A planning and analysis function focusing on data resource management which includes the responsibility of
developing an overall information policy and data architecture for a company’s data resources.
Database Administration:
A data resource management function which includes responsibility for developing and maintaining the
organization’s data dictionary, designing and monitoring the performance of databases, and enforcing standards for
database use and security.
Database Administrator:
A specialist responsible for maintaining standards for the development, maintenance, and security of an
organization’s databases.
Key Field:
A field within a data record that is used to identify it or control its use.
Metadata:
Data about data; data describing the structure, data elements, interrelationships, and other characteristics of a
database.
Query Language:
A high-level human-like language provided by a database management system that enables users to easily extract
data and information from a database.
Report Generator:
A feature of database management system packages, which allows an end user to quickly specify a report format
for the display of information, retrieved from a database.
V. DISCUSSION QUESTIONS
How should an e-business enterprise store, access, and distribute data & information about their internal
operations & external environment?
What roles do database management, data administration, and data planning play in managing data as a
business resource?
What are the advantages of a database management approach to organizing, accessing, and managing an
organization’s data resources?
What is the role of a database management system in an e-business information system?
Databases of information about a firm’s internal operations were formerly the only databases that were
considered to be important to a business. What other kinds of databases are important for a business
today?
What are the benefits and limitations of the relational database model for business applications?
Why is the object-oriented database model gaining acceptance for developing applications and managing
the hypermedia databases at business websites?
How have the Internet, intranets, extranets, and the World Wide Web affected the types and uses of data
resources available to business end users?