DATA RESOURCE MANAGEMENT.docx
DATA RESOURCE MANAGEMENT
Dzulfikar Muhammad A.
Computer science
Semester 2
To understand databases, it is useful to remember that the elements of data that
make up the database are divided into hierarchical levels. These logical data
elements make up the foundation data concepts upon which a database is built.
Character. The most basic logical element is the character, which consists of a
single alphabetic, numeric, or other symbol. While it may take several bits or
bytes to represent a character digitally, remember that these refer to physical
storage, not the logical concept of the character itself.
Field. A field is a grouping of characters that represent a characteristic of a
person, place, thing, or event. A person's name is typically placed in a field. A
field is a data item. A data field represents an attribute or some entity.
Record. A record is a collection of interrelated fields. For example, an
employee's payroll record usually contains several fields, such as their name,
social security number, department, and salary. Records may be fixeddlength or
variabledlength.
File. A file is a collection of interrelated records. For example, a payroll file
might contain all of the payroll files for all the employees of a firm. Files are
usually classified by the application for which they are used.
Database. A database is an integrated collection of logically interrelated records
or files. For example, the personnel database of a firm might contain payroll,
personnel action, and employee skills files. 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.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs. A
database management system (DBMS) is a set of computer programs that
control the creation, maintenance, and use of the databases of an organization
and its end users. Four major DBMS facilities include:
Database Development. A DBMS allows control of development to be placed
with database administrators. The administrator uses a data definition language
(DDL) to develop and specify the data contents, relationships, and structure of
each database, and to modify these specifications when necessary. This
approach improves integrity and security for the organizational databases. The
information is stored in a data dictionary, which uses data definitions to specify
what all the records and files are, can be, and, if desired, to automatically
enforce data element definitions when fields, records, or files are modified.
Database Interrogation. A DBMS allows end users without programming skills to
ask for information from a database using a query language or report generator.
Queries are usually made one of two ways:
SQL (Structured Query Language). This uses the basic form of
SELECT ...FROM...WHERE. After SELECT the user lists the data fields to be
retrieved. After FROM the user lists the files or tables from which the data
must be retrieved. After WHERE the user specifies conditions that limit the
search.
QBE (Query by Example). This method allows users to point and click on
display boxes for each of the data fields in one or more files to specify the
rules of the search
Database Maintenance. Updating the databases and other maintenance are
conducted by transaction processing programs.
Application Development. A DBMS makes application development much easier
and quicker by allowing developers to include data manipulation language (DML)
statements in their programs that let the DBMS perform necessary datadhandling
activities.
Six major types of databases are illustrated on the slide and used by computerd
based organizations:
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. These also
include databases of Internet and electronic commerce activity, such as click
stream data or data describing online behavior of visitors at a company’s
website.
Data Warehouse Databases. These store data from current and previous years
that has been extracted from the various operational and management
databases of the organization. As a standardized and integrated central source
of data, warehouses can be used by managers for pattern processing, where key
factors and trends about operations can be identified from the historical record.
Data Marts. Are subsets of the data included in a Data Warehouse which focus
on specific aspects of a company, e.g. department, business process, etc.
Distributed Databases. These are the databases of local workgroups and
departments at regional ofces, branch ofces, and other work sites needed to
complete the task at hand. They include relevant information from other
organizational databases combined with data and information generated only at
the particular site. These databases can reside on network servers, on the World
Wide Web, or on Intranets and Extranets.
End User Databases. These consist of a variety of data files developed by end
users at their workstations. For example, an end user in sales might combine
information on a customer’s order history with her own notes and impressions
from facedtodface meetings to improve followdup.
External Databases. Many organizations make use of privately generated and
owned online databases or data banks that specialize in a particular area of
interest. Access is usually through a subscription for continuing links or a oned
time fee for a specific piece of information (like the results of a single search).
Other sources like those found on the Web are free.
A data warehouse stores data that has been extracted from various
operational, external, and other databases within the organization.
To create a data warehouse, data from various databases are captured, cleaned,
e.g. sorted, filtered, converted, and transformed into data that can be better
used for analysis. The data is then stored in the enterprise data warehouse,
from where it can be moved into data marts or to an analytical data store that
holds data to support certain types of analysis.
Metadata, that defines the data in the data warehouse, is stored in a Metadata
Directory that is used to support data administration. A variety of analytical
software tools can then be used to query, report, and analyze data.
One such means for analyzing data in a data warehouse is called data mining.
In data mining, the data in a data warehouse are analyzed to reveal hidden
patterns and trends in historical business activity. This can help managers make
decisions about strategic changes in business operations.
The rapid growth of websites on the Internet and corporate intranets and
extranets has dramatically increased the use of databases of hypertext and
hypermedia documents.
Hypermedia Database: A website stores information in a hypermedia database
consisting of a home page and other hyperlinked pages of multimedia or mixed
media (text, graphics and photographic images, video clips, audio segments, and
so on).
Browser: A web browser on your client PC is used to connect with a web network
server. This server runs web software to access and transfer the web pages you
request.
Web Site: A website uses a hypermedia database consisting of HTML (Hypertext
Markup Language) pages, GIF (graphics image files) files, and video files.
Web Server Software: Acts as a database management system to manage the
use of the interrelated hypermedia pages of the website.
The security and integrity of an organization's databases are the major concerns
of the data resource management eforts. Key activities of data resource
management include:
Database Administration. This area is responsible for developing and
maintaining the organization's data dictionary, as well as designing and
monitoring the performance of databases, and enforcing the standards for
database use and security.
Data Planning. Data planning is a corporate planning and analysis function
responsible for the overall data architecture for the firm. This role ensures that
data resources are developed to support the firm's strategic mission and plans.
Data Administration. This area involves the establishment and enforcement of
policies and procedures for managing data as a strategic corporate resource.
This means standardizing data so that it is available to all end users from
whatever database they are working.
The relationships among the records stored in databases are based upon one of
several logical database structures or models. These fundamental database
structures are described below.
Hierarchical Structure. Under this treedlike structure, each data element is
related only to one element above it, a sodcalled onedtodmany relationship. All
records are dependent and arranged in multilevel structures.
Network Structure. This structure features a manydtodmany arrangement
whereby the DBMS can access a data element by following one of several paths.
Relational Structure. This model has become the most popular structure and is
used by most microcomputers. All data elements within the database are
viewed as being stored in the form of simple tables. The DBMS can link data
elements from various tables to provide information to end users.
ObjectdOriented Structure. Objects consist of data values describing the
attributes of an entity and the operations that can be performed on the data.
This is called encapsulation and allows objectdoriented database structures to
better handle complex types of data such as video and audio. The objectd
oriented model also supports inheritance, allowing new objects to replicate some
or all the characteristics of one or more parent objects, as shown in the slide.
Such capabilities allow developers to copy and combine objects, allowing for very
rapid development of new database solutions.
Multidimensional Structure. This structure uses cells within a multidimensional
framework to aggregate data related to elements within a given dimension.
Each cell combines with similar cells to form a coherent "cube" of information
and data, which in turn is combined with other cubes to form dimensions. As a
result they are both compact and easy to understand. Multidimensional
structures have fast become the most popular database structure for analytical
databases that support online analytical processing (OLAP) applications.
Efcient access to data is the critical necessity of an efective database system.
Key concepts and terms associated with file access include:
Key Fields. This is a unique identifier of the data record.
URLs. The files and databases on the Internet and corporate intranets and
extranets use URLs (Uniform Resource Locators) for data access. Thus, pages of
hyperlinked text and multimedia documents on the Web and intranet/extranet
websites are accessed by URLs.
Sequential Organization. This refers to a structure in which the records are
physically stored in a specified order according to a key field in each record.
Sequential Access. This refers to the predetermined order of processing data.
Each record is accessed according to the same set of commands. Access begins
at the start of the file or record and proceeds, in order, to the end. This is a fast
and efcient method for processing large volumes of data.
Direct Access. Under this method, records do not have to be arranged into any
particular sequence on storage media, however the computer must keep track of
the storage location of each record.
Key Transformation. This common direct access technique performs an
arithmetic computation on a key field or record and uses the number that results
as an address to store and access that record.
Indexed Sequential Access Method. This approach combines features of both
sequential and direct access. Sequential storage allows for large volume
processing while indexed addressing allows direct access of smaller amounts of
data from individual records.
Database planning, beyond that of a personal or small business end user
database created by a database management package, typically requires use of
a topddown data planning process based upon the systems development model
covered earlier:
1. Data Planning. At this stage, planners develop a model of business
processes. This results in an enterprise model of business processes with
documentation.
2. Requirements Specification. This stage defines the information needs of end
users in a business process. Description of needs may be provided in natural
language or using the tools of a particular design methodology.
3. Conceptual Design. This stage expresses all information requirements in the
form of a highdlevel model.
4. Logical Design. This stage translates the conceptual model into the data
model of a DBMS.
5. Physical Design. This stage determines the data storage structures and
access methods.
Data resource management is a critical management activity. Management
roles include database administration, data planning, and data administration.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs, serving
multiple users.
Data resource management is a critical management activity. Management
roles include database administration, data planning, and data administration.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs, serving
multiple users.
Dzulfikar Muhammad A.
Computer science
Semester 2
To understand databases, it is useful to remember that the elements of data that
make up the database are divided into hierarchical levels. These logical data
elements make up the foundation data concepts upon which a database is built.
Character. The most basic logical element is the character, which consists of a
single alphabetic, numeric, or other symbol. While it may take several bits or
bytes to represent a character digitally, remember that these refer to physical
storage, not the logical concept of the character itself.
Field. A field is a grouping of characters that represent a characteristic of a
person, place, thing, or event. A person's name is typically placed in a field. A
field is a data item. A data field represents an attribute or some entity.
Record. A record is a collection of interrelated fields. For example, an
employee's payroll record usually contains several fields, such as their name,
social security number, department, and salary. Records may be fixeddlength or
variabledlength.
File. A file is a collection of interrelated records. For example, a payroll file
might contain all of the payroll files for all the employees of a firm. Files are
usually classified by the application for which they are used.
Database. A database is an integrated collection of logically interrelated records
or files. For example, the personnel database of a firm might contain payroll,
personnel action, and employee skills files. 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.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs. A
database management system (DBMS) is a set of computer programs that
control the creation, maintenance, and use of the databases of an organization
and its end users. Four major DBMS facilities include:
Database Development. A DBMS allows control of development to be placed
with database administrators. The administrator uses a data definition language
(DDL) to develop and specify the data contents, relationships, and structure of
each database, and to modify these specifications when necessary. This
approach improves integrity and security for the organizational databases. The
information is stored in a data dictionary, which uses data definitions to specify
what all the records and files are, can be, and, if desired, to automatically
enforce data element definitions when fields, records, or files are modified.
Database Interrogation. A DBMS allows end users without programming skills to
ask for information from a database using a query language or report generator.
Queries are usually made one of two ways:
SQL (Structured Query Language). This uses the basic form of
SELECT ...FROM...WHERE. After SELECT the user lists the data fields to be
retrieved. After FROM the user lists the files or tables from which the data
must be retrieved. After WHERE the user specifies conditions that limit the
search.
QBE (Query by Example). This method allows users to point and click on
display boxes for each of the data fields in one or more files to specify the
rules of the search
Database Maintenance. Updating the databases and other maintenance are
conducted by transaction processing programs.
Application Development. A DBMS makes application development much easier
and quicker by allowing developers to include data manipulation language (DML)
statements in their programs that let the DBMS perform necessary datadhandling
activities.
Six major types of databases are illustrated on the slide and used by computerd
based organizations:
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. These also
include databases of Internet and electronic commerce activity, such as click
stream data or data describing online behavior of visitors at a company’s
website.
Data Warehouse Databases. These store data from current and previous years
that has been extracted from the various operational and management
databases of the organization. As a standardized and integrated central source
of data, warehouses can be used by managers for pattern processing, where key
factors and trends about operations can be identified from the historical record.
Data Marts. Are subsets of the data included in a Data Warehouse which focus
on specific aspects of a company, e.g. department, business process, etc.
Distributed Databases. These are the databases of local workgroups and
departments at regional ofces, branch ofces, and other work sites needed to
complete the task at hand. They include relevant information from other
organizational databases combined with data and information generated only at
the particular site. These databases can reside on network servers, on the World
Wide Web, or on Intranets and Extranets.
End User Databases. These consist of a variety of data files developed by end
users at their workstations. For example, an end user in sales might combine
information on a customer’s order history with her own notes and impressions
from facedtodface meetings to improve followdup.
External Databases. Many organizations make use of privately generated and
owned online databases or data banks that specialize in a particular area of
interest. Access is usually through a subscription for continuing links or a oned
time fee for a specific piece of information (like the results of a single search).
Other sources like those found on the Web are free.
A data warehouse stores data that has been extracted from various
operational, external, and other databases within the organization.
To create a data warehouse, data from various databases are captured, cleaned,
e.g. sorted, filtered, converted, and transformed into data that can be better
used for analysis. The data is then stored in the enterprise data warehouse,
from where it can be moved into data marts or to an analytical data store that
holds data to support certain types of analysis.
Metadata, that defines the data in the data warehouse, is stored in a Metadata
Directory that is used to support data administration. A variety of analytical
software tools can then be used to query, report, and analyze data.
One such means for analyzing data in a data warehouse is called data mining.
In data mining, the data in a data warehouse are analyzed to reveal hidden
patterns and trends in historical business activity. This can help managers make
decisions about strategic changes in business operations.
The rapid growth of websites on the Internet and corporate intranets and
extranets has dramatically increased the use of databases of hypertext and
hypermedia documents.
Hypermedia Database: A website stores information in a hypermedia database
consisting of a home page and other hyperlinked pages of multimedia or mixed
media (text, graphics and photographic images, video clips, audio segments, and
so on).
Browser: A web browser on your client PC is used to connect with a web network
server. This server runs web software to access and transfer the web pages you
request.
Web Site: A website uses a hypermedia database consisting of HTML (Hypertext
Markup Language) pages, GIF (graphics image files) files, and video files.
Web Server Software: Acts as a database management system to manage the
use of the interrelated hypermedia pages of the website.
The security and integrity of an organization's databases are the major concerns
of the data resource management eforts. Key activities of data resource
management include:
Database Administration. This area is responsible for developing and
maintaining the organization's data dictionary, as well as designing and
monitoring the performance of databases, and enforcing the standards for
database use and security.
Data Planning. Data planning is a corporate planning and analysis function
responsible for the overall data architecture for the firm. This role ensures that
data resources are developed to support the firm's strategic mission and plans.
Data Administration. This area involves the establishment and enforcement of
policies and procedures for managing data as a strategic corporate resource.
This means standardizing data so that it is available to all end users from
whatever database they are working.
The relationships among the records stored in databases are based upon one of
several logical database structures or models. These fundamental database
structures are described below.
Hierarchical Structure. Under this treedlike structure, each data element is
related only to one element above it, a sodcalled onedtodmany relationship. All
records are dependent and arranged in multilevel structures.
Network Structure. This structure features a manydtodmany arrangement
whereby the DBMS can access a data element by following one of several paths.
Relational Structure. This model has become the most popular structure and is
used by most microcomputers. All data elements within the database are
viewed as being stored in the form of simple tables. The DBMS can link data
elements from various tables to provide information to end users.
ObjectdOriented Structure. Objects consist of data values describing the
attributes of an entity and the operations that can be performed on the data.
This is called encapsulation and allows objectdoriented database structures to
better handle complex types of data such as video and audio. The objectd
oriented model also supports inheritance, allowing new objects to replicate some
or all the characteristics of one or more parent objects, as shown in the slide.
Such capabilities allow developers to copy and combine objects, allowing for very
rapid development of new database solutions.
Multidimensional Structure. This structure uses cells within a multidimensional
framework to aggregate data related to elements within a given dimension.
Each cell combines with similar cells to form a coherent "cube" of information
and data, which in turn is combined with other cubes to form dimensions. As a
result they are both compact and easy to understand. Multidimensional
structures have fast become the most popular database structure for analytical
databases that support online analytical processing (OLAP) applications.
Efcient access to data is the critical necessity of an efective database system.
Key concepts and terms associated with file access include:
Key Fields. This is a unique identifier of the data record.
URLs. The files and databases on the Internet and corporate intranets and
extranets use URLs (Uniform Resource Locators) for data access. Thus, pages of
hyperlinked text and multimedia documents on the Web and intranet/extranet
websites are accessed by URLs.
Sequential Organization. This refers to a structure in which the records are
physically stored in a specified order according to a key field in each record.
Sequential Access. This refers to the predetermined order of processing data.
Each record is accessed according to the same set of commands. Access begins
at the start of the file or record and proceeds, in order, to the end. This is a fast
and efcient method for processing large volumes of data.
Direct Access. Under this method, records do not have to be arranged into any
particular sequence on storage media, however the computer must keep track of
the storage location of each record.
Key Transformation. This common direct access technique performs an
arithmetic computation on a key field or record and uses the number that results
as an address to store and access that record.
Indexed Sequential Access Method. This approach combines features of both
sequential and direct access. Sequential storage allows for large volume
processing while indexed addressing allows direct access of smaller amounts of
data from individual records.
Database planning, beyond that of a personal or small business end user
database created by a database management package, typically requires use of
a topddown data planning process based upon the systems development model
covered earlier:
1. Data Planning. At this stage, planners develop a model of business
processes. This results in an enterprise model of business processes with
documentation.
2. Requirements Specification. This stage defines the information needs of end
users in a business process. Description of needs may be provided in natural
language or using the tools of a particular design methodology.
3. Conceptual Design. This stage expresses all information requirements in the
form of a highdlevel model.
4. Logical Design. This stage translates the conceptual model into the data
model of a DBMS.
5. Physical Design. This stage determines the data storage structures and
access methods.
Data resource management is a critical management activity. Management
roles include database administration, data planning, and data administration.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs, serving
multiple users.
Data resource management is a critical management activity. Management
roles include database administration, data planning, and data administration.
Under the database management approach, data records are consolidated into
databases that can be accessed by many diferent application programs, serving
multiple users.