Quiz2 Quiz 2 in the second half 1.:Group Presentation: need group name,members(two at the most).Next...

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Transcript of Quiz2 Quiz 2 in the second half 1.:Group Presentation: need group name,members(two at the most).Next...

  • Slide 1
  • Quiz2 Quiz 2 in the second half 1.:Group Presentation: need group name,members(two at the most).Next week (14 th ) lecture in the first half and presentations in the second half.
  • Slide 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
  • Slide 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
  • Slide 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?
  • Slide 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
  • Slide 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
  • Slide 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
  • Slide 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
  • Slide 9
  • Hierarchy of database Bit: 0 or 1 On or Off Byte: typically 8 bits = 1 Byte Character: each byte represent a character (a..z,A..Z,0..9,:;![]()*&^%$#@ ) Field: made up of characters Record: collection of related fields File: A collection of related records Database:A collection of integrated and related files
  • Slide 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
  • Slide 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
  • Slide 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,
  • Slide 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
  • Slide 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
  • Slide 15
  • Data Modeling Key considerations: 1.what data to be stored 2.Who will have access to it 3.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
  • Slide 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
  • Slide 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
  • Slide 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
  • Slide 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
  • Slide 20
  • Customer First Name Last Name ID Number Product Part number Name Color Order 1 N
  • Slide 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)
  • Slide 22
  • Database Models Three logical database models 1.Hierarchical(Tree) Models 2.Network Model 3.Relational Model (most popular)
  • Slide 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
  • Slide 24
  • Hierarchical project Department A Department B Department C Employee 1 Employee 2 Employee 3 Employee 4 Employee 5
  • Slide 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
  • Slide 26
  • Network Models Project 1 Project 2 Department A Department B Department C
  • Slide 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