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Basisdata (Databases)
Williams, B.K, Stacy C. Sawyer (2007).
Using Information Technology: A
Practical Introduction to Computers &
Communications. Seventh Edition,
McGraw-Hill, New York. ISBN-13: 978-007-110768-6
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• menjelaskan: hierarkhi data, key-filed, tipe
file, metode akses dan penyimpanan data;
pengertian dan keuntungan sistem
manajemen basisdata, dan jenis-jenis
akses basisdata yg utama(C2)
2
Outline Materi
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Managing Files: Basic Concepts
Database Management Systems
Database Models
Data Mining
The Ethics of Using Databases
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Managing Files: Basic
Concepts
• A database is a logically organized
collection of related data designed and
built for a specific purpose
• Data is stored hierarchically for easier
storage and retrieval
• Files: collections of related records
• Records: collections of related fields
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Field: unit of data containing 1 or more
characters
Character: a letter number or special
character made of bits
•
Bit: a 0 or 1
8-4
Managing Files: Basic
Concepts
• Key Field – the field that identifies a record
– Often an identifying number, such as social security
number
– Primary keys must be unique
• Keys are used to pick records out of a database
• Unique keys make records stand out from each other
• If two records had the same key, then you might not pick the
correct one
– Nonprimary keys are used to sort records in different ways
– Foreign keys are fields that appear in two different tables and
are used to relate one table to another
8-5
Managing Files: Basic Concepts
8-6
This example
shows a
sample
database in
Microsoft
Access.
Products is a
table.
ProductID is the
primary key of
the Product
table.
ProductID is
also a foreign
key in the
Orders table
Managing Files: Basic Concepts
• Program files are files containing software
instructions
– Source program files are written by the
software developer in the programming
language
• Double-clicking on them won’t run them
• They have file extensions like .cpp, .jav, .bas
– Executable files are program files translated
so they can be executed on the computer
• Double-clicking on them will cause them to run
• They have file extensions like .exe or .com
8-7
Managing Files: Basic Concepts
• Data files are files that contain data such as
words, numbers, pictures, or sounds
– These are the files that are used in databases
– They have extensions such as .txt .mdb, and .xls
– Graphics files have extensions like .tiff, .jpeg, and
.png
– Audio files have extensions such as .mp3, .wav, and
.mid
– Animation/video files have extensions such as .qt,
.mpg, .avi, and .rm
• Data files are often compressed to save space
and transmit them faster
– Compression removes repetitive elements from a file
8-8
Database Management Systems
• Software written specifically to control the
structure of a database and access to the data
– Reduced data redundancy
• Redundant data is stored in multiple places, which causes
problems keeping all the copies current
– Improved data integrity
• Means the data is accurate, consistent, and up to date
– Increased security
• Limits who can create, read, update, and delete the data
– Ease of data maintenance
• Offer validation checks, backup utilities, and procedures for
data inserting, updating, and deletion
8-9
Database Management Systems
3 Principal Components
• Data Dictionary
– A repository that stores the data definitions and
descriptions of the structure of the data and the
database
• DBMS Utilities
– Programs that allow you to maintain the database by
creating, editing, deleting data, records, and files
– Also include automated backup and recovery
• Report Generator
– Program for producing an on-screen or printed
document form all or part of a database
8-10
Database Management Systems
Database Administrator
• Database Administrator (DBA)
– A high-paid, responsible position within an
organization
– Coordinates all related activities and needs for an
organization’s database
– Ensures the database’s
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Discussion Question: Did
you know that 93% of
companies that lost their
data center for 10 days or
more due to a disaster filed
for bankruptcy within a
year?
Recoverability
Integrity
Security
Availability
Reliability
Performance
8-11
Database Management Systems
Database Administrator
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U.S. businesses lose over $12 billion per year because of data loss.
Hardware or system failure accounts for 78% of all data loss.
Human error accounts for 11% of all data loss.
Software corruption account for 7% of all data loss.
Natural disasters account for only 1% of all data loss.
More vital data is being stored in smaller spaces.
Instant access to electronic data has become more crucial in day-to-day
business.
Disaster prevention and recovery plans are often overlooked or outdated.
Backup tools and techniques are not 100% reliable.
93% of companies that lost their data center for 10 days or more due to a
disaster filed for bankruptcy within one year of the disaster.
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Database Models
• Hierarchical Databases
– Fields or records are arranged in related groups resembling a family
tree with child (low-level) records subordinate to parent (high-level)
records
– Root record is the parent record at the top of the database, and data
is accessed through the hierarchy
– Oldest and simplest; used in mainframes
8-13
Database Models
• Network Database
– Similar to a hierarchical database, but each child record can have
more than one parent record
– Used principally with mainframe computers
– Requires the database structure to be defined in advance
8-14
Database Models
• Relational Database
– Relates or connects data in different files through the
use of a key, or common data element
– Examples are Oracle, Informix, Sybase
– Data exists independently of how it is physically
stored
– Users don’t need to know data structure to use the
database
– Uses SQL (structured query language) to create,
modify, maintain, and query the data
– Query by Example uses sample records or forms to
allow users to define the qualifications for choosing
records
8-15
Database Models
• Object-oriented Databases
– Use “objects”, software written in small, manageable
chunks, as elements within data files
– An object consists of
• Data in any form, including audio, graphics, and video
• Instructions on the action to be taken with the data
– Examples include FastObjects, GemStone, Objectivity
DB, Jasmine Object Database, and KE Express
– Types include
• Web database
• Hypermedia database
8-16
Database Models
• Multidimensional Database
– Models data as facts, dimensions, or
numerical answers for use in the interactive
analysis of large amounts of data for decisionmaking purposes
– Allows users to ask questions in colloquial
English
– Use OLAP (Online Analytical Processing)
software to provide answers to complex
database queries
8-17
Data Mining
• Is the computer-assisted process of sifting
through and analyzing vast amounts of data to
extract hidden patterns and meaning and to
discover new knowledge
• Data is fed into a Data Warehouse through the
following steps
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Identify and connect to data sources
Perform data fusion and data cleansing
Obtain both data and meta-data (data about the data)
Transport data and meta-data to the Data Warehouse
• Data Warehouse is a special database that
shows detailed and summary data from multiple
sources
8-18
Data Mining
• Methods for searching for patterns in the
data and interpreting the results
– Regression analysis
• Develops a formula to fit patterns in the data that
has been extracted
• Formula is applied to other data sets to predict
future trends
– Classification analysis
• A statistical pattern recognition process that is
applied to data sets with more than just numerical
data
8-19
Data Mining
• Applications include
– A phone company identifying customers with
large bills, who were really small businesses
trying to pay the cheaper residential rate
– A coach in the Gymnastics Federation used it
to discover what long-term factors contributed
to athletes’ performance
– Retail stores use it to predict future purchase
patterns to help them choose which products
to stock for the future
8-20
The Ethics of Using Databases
• Identity Theft concerns
– A crime in which thieves hijack your identity
and use your good credit rating to get cash,
take out loans, order credit cards, and buy
things in your name
• Privacy concerns
– Name migration: getting endless junk mail
and telemarketing calls
– Résumé rustling and online snooping
– Government prying and spying
Discussion Question: Has any one had their identity stolen? How long did it take
you to get it straightened out?
8-21
Kesimpulan
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