Transcript Data

Introduction to Databases
Chapter 1:
Introducing Data and
Data Management
Data
• Stream of raw, unorganized facts
• Single piece of data is single fact:
– Refrigerator SSN 958304 manufactured
11/05/2006
• Information: Data organized into form
people can understand or use
Databases
• Ordered collections of related data
elements
• Designed to meet organization’s
information needs
• Designed to be shared by multiple users
• Help transform data into information
– For example, used to transform store cash
register transactions into sales reports
Example: Airline Ticketing & Reservations Company
Example: Airline Ticketing & Reservations Company
Data Management
• Uses databases and database
management software (DBMS)
• Allows organizations to:
– Easily access data
– Handle greater quantities of data
– Share data
– Reduce data redundancy (unwanted duplicate
data)
Data Sources
• To understand what data is meaningful,
examine company’s core business and
processes
• Processes: Series of tasks that accomplish
specific goal
• Primary processes help fulfill core
business
• To carry out process, company needs
resources and assets, such as:
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Buildings and equipment
People
Money
Information from relevant data sources
Example: Car Rentals
• Core business
– Rent cars
• Primary processes
– Processes to manage fleet and service cars
Example: Car Rentals: Departmental Activities
Specific Data Sources
• Specific data important to company can be
found in:
– Current information held in business
documents
– Historic information
– Human sources: Employees at different levels
can provide different types of information about
data
Human Data Sources
Data Flows
• Part of data collection process includes
understanding how data flows through
organization
• Data: Similar to water, flowing from source
to destination
• However, unlike river, data may have
many destinations, or data consumers
Data Concerns
• Data accuracy
• Data security
• Data organization
• Data access
Data Accuracy
• Involves ensuring accurate and correct
data
• Inaccurate data:
– Employee mistakes, shortcuts, and biases
– Outdated
– Poorly designed formulas or algorithms
• Maintaining data accuracy includes:
– Verifying data sources
– Managing data entry and manipulation
Data Security
• Processes and procedures implemented
with goal of keeping data safe
• Basic data security categories include:
– Access security
– Physical security
Access Security
• Involves controlling user and application
access to data, usually through one or
more authentication methods
• To reduce data source’s vulnerability:
– Reduce surface area (how exposed database
is to access and manipulation by consumer
audience)
• As potential consumer audience
increases, so do potential security
concerns
Access Security
Physical Security
• Involves protecting data against physical
corruption or loss
• Three basic tasks :
– Protecting server
• Secure server in locked room with limited access
– Ensuring storage media
• Use fault-tolerant disk system
– Duplicating data
• Maintain duplicate of data on mirror image, or make
data backups
Data Organization
• Forces structure on data
• Helps reduce amount of physical space
data requires
• Helps minimize time required to locate and
retrieve data
• Data standards: Help ensure that right
amount of data is entered in same way for
every data object
Data Access
• Data queries retrieve data, insert new
data, or manipulate existing data
• Before database setup, determine:
– Who needs access to data
• User roles or responsibilities
– What level of access is needed
• Full or limited access
– Type of access needed
• Directly or indirect through separate application
Summary
• Data are raw facts that organizations
collect and transform into meaningful
information
• Data and information are primary business
resource
• Data management through databases help
support business’s primary processes and
core business
• Data management concerns include data
accuracy, data security, data organization,
and data access
Key Terms
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Access security
Authentication method
Consumer audience
Core business
Data
Data access
Data accuracy
Data consumer
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Data query
Data security
Database
Fault-tolerant disk
system
Information
Mirror image
Physical security
Surface area
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