1. Quiz2 Quiz 2 in the second half
:Group Presentation: need group name,members(two at the most).Next week (14th) lecture in the first half and presentations in the second half.

2. Organizing Data and Information
Objectives: Define general data management concepts and terms, highlighting the advantages and disadvantages of the database approach to data management
Name three database models and outline their basic features, advantages, and disadvantages
Identify the common functions performed by all database management systems and identify three popular end-user database management systems

3. Principles
The database approach to data management provides significant advantages over the traditional file-based approach
A well designed and well managed database is a valuable tool in supporting decision making

4. Thought provoking
How can database be used to support critical business objectives?
What are some of the issues associated with compiling and managing massive amounts of data?

5. Catalina Marketing Corporation
Supplier of in-store electronic scanner-activated consumer promotions.Provide marketing services to consumer goods companies
Its network provides Individually customized communications and promotions based on customer purchases
The network uses Actual purchase behavior to target the future buying behavior
shopping pattern of 150 million shoppers each week in more than 11,000 supermarkets captured and stored in its enormous database,2 Tb.The database has 18 Billion rows of data,for past 65 weeks
Each retailer that subscribe to Catalina has a PC in the supermarket
Catalina pools this pc nightly via a data network
70 million rows of data of that day purchase loaded into database

6. Catalina Marketing Corporation
Catalina also downloads to that store pc the information about targeted promotion scheduled for the next day
As items are scanned at the checkout counter, the PC flags any item or the shopper, if the store has a loyalty program– eligible for promotion
A printer at checkout counter prints out a targeted coupon ,rebate, in-store game, or other incentive
Two customers buying the same product can get different offers
Occasional user can have a coupon while a user of competitive product may get a free sample
Coupon redemption rates 0.6%,4.3%, 8.9% for magazine and newspaper,direct mail, Catalina marketing

7. The Catalina Marketing Network program also arms consumer-goods manufacturers and supermarket retailers with Stealth Campaign
A latest marketing weapon,the act of moving in a covert(secret) way
Stealth marketing lets manufacturers and retailers promote specific items and judge campaign effectiveness without their competitors ever knowing that a promotion took place.
Traditional advertising tools;newspapers,radio,and TV.inform consumer,but also alert competitors

8. Database Management System
Throughout your career, you will be accessing a variety of databases
Simple roster of departmental employees
Fully integrated corporatewide database
DBMS: A software to access database
It consists of a group of programs that manipulate the database
Provides an interface to the users and application programs to talk to underlying database
Database environment:database,DBMS,and application programs
Knowledge of database can enhance your ability to use computerized database systems to support IS and org. goals

9. Hierarchy of database Bit: 0 or 1 On or Off
Byte: typically 8 bits = 1 Byte
Character: each byte represent a character )
Field: made up of characters
Record: collection of related fields
File: A collection of related records
Database:A collection of integrated and related files

10. Data Entities,Attributes, Keys
Entity:
generalized class of people, places, or things for which data is collected , stored, and maintained
Attribute:
characteristic of an entity
Data item:
specific value of an attribute
Key:
A field or set of fields in a record that is used to identify the record
Primary Key:a field or set of fields that uniquely identifies the record

11. Traditional Approach
Manage data via separate data files for each application program
Payroll file , invoicing file, customer, inventory file
Flaws : data redundancy (customer name & address)
Data Integrity: how accurate data is (keeping customers address in only one file
Drawback: Program data dependencies:In computerized database systems, data organized for a particular program(say billing)
Example: zip code format five numbers,other has nine number-format

12. Database Approach
A pool of related data is shared by multiple application programs
Have tables which contain records, e.g. employee, project,items, and customers
RDBMS: relational database management system
Advantages:
Improved strategic use of corporate data:
accurate,complete,up-to-date is available to decision makers, when and where they need it
no data redundancy: stored in one location
efficient usage of storage space ,data integrity,

13. Advantages
sharing data,information resources: cost of hardware , software , and DBA,data entry operator, and programmers spread over a large number of applications and users
Easier: centrally monitored, controlled, edited
Enhanced security
Standardization of data access: primary feature,same procedures are used by all application programs to retrieve data and information

14. Disadvantages
If for some reason there is a failure in DBMS, all programs are affected
If security is breached more data is accessible to unwanted persons
Mainframe DBMS cost hundreds of thousands of dollars
Specialized staff required

15. Data Modeling Key considerations: what data to be stored
Who will have access to it
How to use data
Then create the database
Building a database requires two different types of designs logical design and physical design
Logical design: every thing starts with logic

16. Logical Design
shows an abstract model how data should be structured, and arranged to meet ORG information needs
Identifying relationships among different data items and grouping them in an orderly fashion
Database is used by IS ,and IS is used throughout an org , users assist in logical design

17. Physical Design Based on logical design
Fine-tunes it for performance and cost consideration
Examples: improved response time, DBMS can tell you the time your query took, e.g. 3seconds improve it
reduced storage space, lower operating cost
Logical design could be altered, some data attribute are repeated in more than one entity
Is this not redundant?
Yes we call it planned data redundancy
It is done to speed up the user reports or queries

18. Data Model
Data Mode:Tool database designers use to show the logical relationships among data
A diagram of entities and their relationships
Data modeling involves understanding a specific business problem
Analyzing data and information needed to deliver a solution
Enterprise data modeling: when scope is entire org
Starts with finding data and information needs of the org at strategic level and specific needs for various functional areas

19. Entity-Relationship (ER) diagrams
Use graphic symbols to show the organization of data and relationship between data
Box: for entity
Diamond: relationship between entities
Oval: attribute
Types of relationship between entities
one to one
One to many
Many to many

20. First
Name
Last
Name ID
Number
Customer 1
Order N
Product
Name
Part
number
Color

21. MySQL
Open source DBMS
Execute mysql (already installed ,created databases, and tables)
Command: show databases; (end with ;)
Use se452; (se452 is a database)
Show tables;
Describe address; (address is a table in se452 database) show attributes and their types
Select * from address; shows all records in the table
mysql > insert into address values(12,"B 71 block 10 Gulshan");
query OK, 1 row affected (0.03 sec)

22. Database Models Three logical database models
Hierarchical(Tree) Models
Network Model
Relational Model (most popular)

23. Hierarchical
Data is organized in a top-down, or inverted tree,structure
Must follow a definite path (searching a record is slow)
To Best suited One-to-many relationship among the elements
Parent children

24. Hierarchical project Department C Department A Department B Employee 12
Employee 3
Employee 4
Employee 5

25. Network Models Expansion of the hierarchical model
Owner-member relationship
Member may have many owners
Deficiency : once relationships are established between data elements , it is difficult to modify them or to create new relationships
Many-to-many relationship among the elements

26. Network Models Project 1 Project 2 Department A Department B

27. Relational Models Tabular format
All data elements are placed in two-dimensional tables, called relations
Relation: Logical equivalent of files
Tables: rows and columns
Each row represents a data entity,columns represent attributes
Each attribute can have only one value (data types char, varchar, number)
Domain: allowable values for attributes e.g. gender M or F
Pay rate can not be negative numbers e.g. -$5.0 can not be entered into database

28. Once database and its tables are created we can populate these tables with records
Can query a database about the records
Selection: shows only those records according to a specific criteria (works on rows)
Select * from employees where salary > 2000 ;
Projection:works on columns, eliminating columns based on a specific criteria
Joining: combining two or more tables
Linking: combining two or more tables using common attributes to form a new table with only the unique data attributes ; power and flexibility of RDB

29. Many company use it for large corporate database, such as marketing and accounting
Relational model can be used with PC and mainframe systems

30. Data Cleanup
Database created with data from multiple sources, those disparate sources may store different values for the same customer due to spelling errors, multiple account numbers, and address variations
Purpose of data cleanup is to look for and fix these and other inconsistencies that can result in duplicate or incorrect records ending up in the database

31. DBMSs
A group of programs used as an interface between database and application programs or
A database and the user
DBMSs classified by the database model they support
Example: A relational database management system follows the relational model
Access by Microsoft for PC
Mainframe RDBMSs include DB2 by IBM, Oracle, Sybase, and Informix.
Common functionalities: user view, creating and modifying, storing and retrieving data, manipulating data, and generating reports

32. User View
DBMS must know the logical and physical structure of the data and the relationship among the data in the database
Schema: A description of the entire database
Can be a separate file
Can be part of the database
Subschema: A file that contains a description of a subset of the database and identifies which users can view and modify the data items in the subset
Programmers and managers needs only a subset of the database
Example: a sales representative might need only data describing customers in her region, not the sales data for the entire nation

33. DBMS
Schema
Subschema A
Subschema B
Subschema C
User 1
User 2
User 3
User 4
User 5
User 6

34. Creating and Modifying Database
Schema and subschemas are entered into database via DDL
DDL: A data definition language
DDL: a collection of instructions and commands used to define and describe data and data relationships in a specific database
In general , a DDL describes logical access paths and logical records in the database