databases
TRANSCRIPT
![Page 1: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/1.jpg)
Chapter 3Organizing Data and Information
![Page 2: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/2.jpg)
Introduction
Database: an organized collection of data
Database management system (DBMS): group of programs to manage databaseManipulates databaseProvides an interface between database and
the user of the database and other application programs
Database administrator (DBA): skilled IS professional who directs all activities related to an organization’s database
![Page 3: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/3.jpg)
The Hierarchy of Data
Bit (a binary digit): a circuit that is either on or off
Byte: eight bits Character: basic building
block of information Each byte represents a
character Can be an uppercase letter,
lowercase letter, numeric digit, or special symbol
Field: typically a name, number, or combination of characters that describes an aspect of a business object or activity
Record: a collection of related data fields
File: a collection of related records
Database: a collection of integrated and related files
Hierarchy of data: bits, characters, fields, records, files, and databases
![Page 4: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/4.jpg)
The Hierarchy of Data
Figure 3.1: The Hierarchy of Data
![Page 5: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/5.jpg)
Data Entities, Attributes, and KeysEntity: a generalized class of people, places, or
things (objects) for which data is collected, stored, and maintained
Attribute: characteristic of an entityData item: value of an attributeKey: field or set of fields in a record that is
used to identify the recordPrimary key: field or set of fields that uniquely
identifies the record
![Page 6: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/6.jpg)
Data Entities, Attributes, and Keys
Figure 3.2: Keys and Attributes
![Page 7: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/7.jpg)
The Database Approach
Traditional approach to database management: separate data files are created for each applicationResults in data redundancy (duplication)
Data redundancy conflicts with data integrity
Database approach to database management: pool of related data is shared by multiple applicationsSignificant advantages over traditional approach
![Page 8: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/8.jpg)
The Database Approach
Figure 3.3: The Database Approach to Data Management
![Page 9: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/9.jpg)
The Database Approach
![Page 10: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/10.jpg)
The Database Approach
Table 3.2: Disadvantages of the Database Approach
![Page 11: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/11.jpg)
Data Modeling and the Relational Database Model
When building a database, consider:Content: What data should be collected, at what
cost?
Access: What data should be provided to which users and when?
Logical structure: How should data be arranged to make sense to a given user?
Physical organization: Where should data be physically located?
![Page 12: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/12.jpg)
Data Modeling
Building a database requires two types of designsLogical design
Abstract model of how data should be structured and arranged to meet an organization’s information needs
Physical designFine-tunes the logical database design for
performance and cost considerations
![Page 13: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/13.jpg)
Data Modeling
Data model: a diagram of data entities and their relationships
Entity-relationship (ER) diagrams: data models that use basic graphical symbols to show the organization of and relationships between data
![Page 14: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/14.jpg)
The Relational Database Model Relational model: all
data elements are placed in two-dimensional tables (relations), which are the logical equivalent of files
In the relational model Each row of a table
represents a data entity
Columns of the table represent attributes
Domain: the allowable values for data attributes
![Page 15: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/15.jpg)
Manipulating Data
Figure 3.7: Linking Data Tables to Answer an Inquiry
![Page 16: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/16.jpg)
Database Management Systems (DBMS)
Interface between:Database and application programs Database and the user
Creating and implementing the right database system ensures that the database will support both business activities and goals
DBMS: a group of programs used as an interface between a database and application programs or a database and the user
![Page 17: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/17.jpg)
Overview of Database Types
Flat fileSimple database program whose records have no
relationship to one another
Single userOnly one person can use the database at a timeExamples: Access, FileMaker, and InfoPath
Multiple userAllows dozens or hundreds of people to access the
same database system at the same timeExamples: Oracle, Sybase, and IBM
![Page 18: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/18.jpg)
Creating and Modifying the Database
Data definition language (DDL) Collection of
instructions/commands that define and describe data and data relationships in a database
Allows database creator to describe the data and the data relationships that are to be contained in the schema
Data dictionary: a detailed description of all the data used in the database
![Page 19: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/19.jpg)
Storing and Retrieving Data When an application requests
data from the DBMS, the application follows a logical access path
When the DBMS goes to a storage device to retrieve the requested data, it follows a path to the physical location (physical access path) where the data is stored
![Page 20: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/20.jpg)
Manipulating Data and Generating Reports
Query-By-Example (QBE): a visual approach to developing database queries or requests
Data manipulation language (DML): commands that manipulate the data in a database
Structured Query Language (SQL): ANSI standard query language for relational databases
Database programs can produce reports, documents, and other outputs
![Page 21: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/21.jpg)
Database Administration
Database administrator (DBA): directs or performs all activities to maintain a database environmentDesigning, implementing, and maintaining
the database system and the DBMSEstablishing policies and proceduresEmployee training
![Page 22: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/22.jpg)
Popular Database Management Systems
Popular DBMSs for end users: Microsoft Access and FileMaker Pro
Entire market includes databases by IBM, Oracle, and Microsoft
Examples of open-source database systems: PostgreSQL and MySQL
Many traditional database programs are now available on open-source operating systems
![Page 23: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/23.jpg)
Selecting a Database Management System
Important characteristics of databases to considerSize of the databaseCost of the systemNumber of concurrent usersPerformanceAbility to be integrated with other systemsVendor considerations
![Page 24: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/24.jpg)
Using Databases with Other Software
Database management systems are often used with other software packages or the Internet
A database management system can act as a front-end application or a back-end applicationFront-end application: interacts with users Back-end application: interacts with
applications
![Page 25: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/25.jpg)
Linking Databases to the Internet
Linking databases to the Internet is important for many organizations and people
Semantic Web Developing a seamless integration of traditional databases with
the Internet
Allows people to access and manipulate a number of traditional databases at the same time through the Internet
![Page 26: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/26.jpg)
Data Warehouses, Data Marts, and Data Mining
Data warehouse: collects
business information from
many sources in the
enterprise
Data mart: a subset of a data
warehouse
Data mining: an information-
analysis tool for discovering
patterns and relationships in a
data warehouse or a data mart
![Page 27: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/27.jpg)
Data Warehouses, Data Marts, and Data Mining
Table 3.5: Common Data-Mining Applications
![Page 28: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/28.jpg)
Business Intelligence
Business intelligence (BI): gathering the right information in a timely manner and usable form and analyzing it to have a positive impact on business Turns data into useful
information that is then distributed throughout an enterprise
Competitive intelligence: aspect of business intelligence limited to information about competitors and the ways that knowledge affects strategy, tactics, and operations
Counterintelligence: steps an organization takes to protect information sought by “hostile” intelligence gatherers
![Page 29: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/29.jpg)
Distributed Databases
Distributed databaseData may be spread across several smaller
databases connected via telecommunications devices
Corporations get more flexibility in how databases are organized and used
Replicated databaseHolds a duplicate set of frequently used data
![Page 30: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/30.jpg)
Online Analytical Processing (OLAP)
Software that allows users to explore data from a number of different perspectives
Table 3.6: Comparison of OLAP and Data Mining
![Page 31: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/31.jpg)
Object-Oriented and Object-Relational Database Management Systems
Object-oriented databaseStores both data and its processing
instructionsMethod: a procedure or actionMessage: a request to execute or run a
method
![Page 32: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/32.jpg)
Visual, Audio, and Other Database Systems
Visual databases for storing images Audio databases for storing sound Virtual database systems: allow different databases
to work together as a unified database system Other special-purpose database systems
Spatial data technology: stores and accesses data according to the locations it describes and permits spatial queries and analysis
![Page 33: Databases](https://reader035.vdocument.in/reader035/viewer/2022062513/5554a410b4c905fd608b4d1b/html5/thumbnails/33.jpg)
Video Clip
ChoicePointhttp://www.youtube.com/watch?v=bWB3kEw08
Gk