information and databases chapter outline 4 data modeling: documenting information architecture 4...
TRANSCRIPT
![Page 1: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/1.jpg)
Information and Databases
![Page 2: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/2.jpg)
Chapter Outline
Data Modeling: Documenting Information Architecture
User’s View of a Computerized Database Database Management Systems Text Databases and Hypertext Evaluating Information Used in Business
Processes Models as Components of Information Systems
![Page 3: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/3.jpg)
Data Modeling: Documenting Information Architecture Entity-Relationship Diagrams Identifying the Data in Information Systems
![Page 4: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/4.jpg)
An information architecture
What information is in a system? How is the information organized? How can users get the information they
want? Are these points independent? How can we represent this? Do we need a
tool?
![Page 5: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/5.jpg)
A model for representing information and relationships What kinds of things are important in this
system? How are these things (entities) related? What information (attributes) are collected
about these things?
![Page 6: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/6.jpg)
Entity Relationship Diagram
![Page 7: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/7.jpg)
So…what do these symbols mean?
![Page 8: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/8.jpg)
Symbols in an ERD
![Page 9: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/9.jpg)
Attributes (information) about our entities (from Alter pp. 113)
DEPARTMENT•Department identifier•College•Department head•Scheduling coordinatorCOURSE•Course number•Department •Required of department major (y/n)•Course descriptionSECTION•Section identification number•Semester•Year•Classroom•Start time•End time•Days of week for class meetings
PROFESSOR•Employee identification number•Name•Address•Birthdate•Office telephone•Social Security numberSTUDENT•Student identification number•Name•Address•Birthdate•Telephone•Gender•Ethic group•Social Security numberOFFICE•Office number•Building•Telephone extension
![Page 10: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/10.jpg)
What other attributes may be needed What needs to be added? What needs to be changed? What are common attributes that can be
used to “join” the tables? For class Thursday, have an idea of how
you think these entities could be improved…we are going to spend some time setting up a database
![Page 11: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/11.jpg)
User’s View of a Computerized Database Types of Data What is a Database? What is a File? Relational Databases Geographic Information Systems
![Page 12: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/12.jpg)
Types of data…
Formatted data items Text Images Audio Video
![Page 13: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/13.jpg)
What is a database?
A structured collection of items stored, controlled and accessed through a computer based on predefined relationships between predetermined data types.
What are some examples of databases that you are familiar with?
NOT a DBMS!
![Page 14: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/14.jpg)
Files and records and fields...
File– A set of records
Record– A set of fields
Field– A group of characters with a predefined meaning
Key– A field that uniquely identifies an entity
![Page 15: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/15.jpg)
Relational Databases
“A set of two-dimensional tables in which one or more key-fields in each tables are associated with corresponding key or non-key fields in other tables.”
Normalization– eliminating redundancies from tables in the
database
Typically accessed via SQL
![Page 16: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/16.jpg)
Other types of databases
Geographical Information Systems– becoming quite important for county and local
governments– Locally, Orange County and the Town of
Chapel Hill are looking for ways to integrate GIS data with their information systems
Image/video databases
![Page 17: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/17.jpg)
Database Management Systems
Defining the Database Methods for Accessing Data in a Computer
System Processing Transactions Controlling Distributed Databases Backup and Recovery
![Page 18: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/18.jpg)
So…what is a DBMS?
Examples– Oracle– Sybase– Access
Makes data more of an enterprise resource and makes programming work more effective/efficient
![Page 19: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/19.jpg)
Defining the database and Access to Data Data definition
– kept in a data dictionary• Metadata (data about data!)
– Data definition for a database is a schema
DBMS Access– typically will be some form of indexed access
– sometimes, sequential access is useful• less flexible
– controlled by the DBMS to minimize complexity
![Page 20: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/20.jpg)
Indexed access
![Page 21: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/21.jpg)
Transaction processing
Small section in the book, but very important– provides control for logical units of work– locks resources– manages concurrency– provides queuing and prioritization
Can be in the DBMS or a separate transaction server
![Page 22: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/22.jpg)
Controlling Distributed Databases Replication
– decentralized storage of information
Two-phase commit– maintain consistency– try to protect data from network or system
failures
![Page 23: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/23.jpg)
Backup and recovery
Backup is often neglected Disaster recovery plans are often non-
existent– Why do you need a disaster recovery plan?– What is in such a plan?
![Page 24: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/24.jpg)
Review of things covered so far...
A model for describing information in a system and the relationships– the ERD
What is a database? What is a DBMS? What is a transaction processing system? What about backup and recovery?
![Page 25: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/25.jpg)
Hands-on Lab: Building a database Use your modified table 4.2 (from Alter,
page 113) Create tables in Access for the entities Establish appropriate relationships Populate with sample information
![Page 26: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/26.jpg)
Text Databases and Hypertext
Hypertext Browsers Indexes and Search Engines
![Page 27: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/27.jpg)
Hypertext
Most common example today is HTML– HyperText Markup Language
Web combines hypertext and multimedia to be a “hypermedia” system
Let’s look at some HTML– This may be a review for many, but bear with
us so we can all reach a common level of understanding
![Page 28: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/28.jpg)
The HTML for our class main page
<!doctype html public "-//w3c//dtd html 4.0 transitional//en"><html><head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="GENERATOR" content="Mozilla/4.7 [en] (Win98; I) [Netscape]"> <meta name="Author" content="Joel Dunn"> <title>INLS60, Fall 2000</title></head><body bgcolor="#FFFFFF">
<center>School of Information and Library Science<br>University of North Carolina at Chapel Hill</center>
<center><h2>INLS60<br>Information Systems Analysis and Design<br>Fall 2000</h2></center>
<center>Tuesday/Thursday 2:00-3:15PM<br>307 Manning<br>Joel Dunn<br>[email protected]<br>Office - 440 W. Franklin St., Rm. 07<br>Phone: Office - 966-5837; Home - 968-1911<p><a href="F00-Syllabus.html">Syllabus</a> / <a href="F00-Calendar.html">Calendar</a>/ <a href="F00-Assignments.html">Assignments</a> / <a href="F00-Comm.html">Communications</a></center>
<p><hr ALIGN="CENTER"><b>Course Description:</b><p>Analysis of organizational problems and how information systems canbe designed to solve those problems. Application of database and interfacedesign principles to the implementation of information systems.<p><hr ALIGN="CENTER"><p><i>Last modified 3 August, 2000</i><br><i><a href="mailto:[email protected]">Joel Dunn</a></i></body></html>
![Page 29: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/29.jpg)
How does the browser fit in?
Retrieve pages from the text databases of Web servers
Act as today’s defacto standard terminal for other types of database access– http://bullhead.ais.unc.edu/cgi-bin/waisretrieve.pl?1301425xxx1303956xx
x/home/longlegs/flyfish/log00/log0001d.txt:flyfish00
Provide vector to launch applets Provide access to servlets Both applets & servlets are used for data access
![Page 30: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/30.jpg)
Overview of Java ServletsJava Servlets
LM/W
P L
M/W
Web ServerClient
Name: SmithSSN: 111-22-3333
Enter
import javax.servlet.*;class MyServlet extends GenericServlet { public void service( ServletRequest request, ServletResponse response ) throws ServletException, IOException {...}}
Program that runs on Web Server, Registered with Web ServerNo graphical User Interface (HTML)Less resource-intensive than CGI programs (load once, run many) Portable to other Web Servers, positioning for future EJBsPart of JDK 1.1 as a Standard Java Extension API
(GenericServlet, HTTPServlet class)Can be programmed to access existing applications, dist. objects, etc.Can be used to improve end-to-end performanceCan be used to address firewall concern
![Page 31: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/31.jpg)
Let’s review the basic model of browser/server interaction
![Page 32: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/32.jpg)
Indexes and search engines
In the web context, what is an index? What does a search engine do?
– How is a search engine like a DBMS?
How has the pervasiveness of hypertext and web-based searching changed the way we deal with collections of information?
What are your favorite search engines, and why?
![Page 33: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/33.jpg)
Evaluating Information Used in Business Processes Information Quality Information Accessibility Information Presentation Information Security
![Page 34: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/34.jpg)
Information quality
INFORMATION QUALITY
•ACCURACY
•PRECISION
•COMPLETENESS
•AGE
•TIMELINESS
•SOURCE
•What are some examples of these qualities?
![Page 35: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/35.jpg)
Information accessibility, presentation and security
INFORMATION ACCESSIBILITY
•AVAILABILITY
•ADMISSIBILITY
INFORMATION PRESENTATION
•LEVEL OF SUMMARIZATION
•FORMAT
INFORMATION SECURITY
•ACCESS RESTRICTION
•ENCRYPTION
![Page 36: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/36.jpg)
Let’s think about a database and evaluate it based on these criteria What about your academic record, your
history of courses taken and grades received here at UNC?
![Page 37: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/37.jpg)
Models as Components of Information Systems Mental Models and Mathematical Models What-if Questions
![Page 38: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/38.jpg)
Models…
A part of the decision making process
![Page 39: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/39.jpg)
A mental model…how you think things work...
![Page 40: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/40.jpg)
Mathematical model
Series of equations/algorithms that describe relationships between variables
Is often an instantiation of a mental model in an information system to apply data to solve a problem
![Page 41: Information and Databases Chapter Outline 4 Data Modeling: Documenting Information Architecture 4 User’s View of a Computerized Database 4 Database Management](https://reader036.vdocuments.mx/reader036/viewer/2022062516/56649e575503460f94b504aa/html5/thumbnails/41.jpg)
What-if Questions
Enabled by mathematical models How things could operate given a change in
circumstances Discussion item…
– how might we try to build a model to examine the impact of dramatically increased enrollment at UNC over the next 10 years? What elements would we put in our model; what would we exclude?