1. Database Design – Lecture 18 Client/Server, Data Warehouse and E-Commerce Database Design

2. 2 Lecture Objectives Client/Server Data Warehouse E-Commerce

3. 3 Client/Server A computing model/architecture Functionality is distributed between servers and clients Client is the TP (transaction processor) Server is the DP (data processor) Data can be distributed on more than one physical site (location) but not necessarily

4. 4 Client/Server If data is distributed then the following characteristics are required: Location of data must be transparent to the user (I.e. database must have DDBMS characteristics) Data can be accessed and manipulated by the user at any time and in any way (I.e. data requested is processed by the server but the formatting and presentation are done on the client side)

5. 5 Client/Server If data is distributed then the following characteristics are required: Processing of data is distributed amongst multiple computers (I.e. data can reside at multiple locations, the DDBMS server will locate it and assemble it and send it back to client)

6. 6 Client/Server Database Design Issues No significant issues – conceptual modeling used to form the basis for the database design Placement of the data is critical to ensure a balance across this architecture

7. 7 Client/Server - Tiers 2-Tier Client requests services directly from the server only 3-Tier Client requests hare handled by intermediate servers, which co-ordinate the clent request with subordinate servers i.e. Client – Database Middleware – Database Server

8. 8 Client/Server - Tiers Multi-Tier Client request are handled by intermediate servers, which co-ordinate the client requests with subordinate servers i.e. Client – Application Server (WebLogic, WebSphere) – Database Middleware – Database Server)

9. 9 Client/Server Database Middleware Provides the connectivity between application software and the database Client application Standard ODBC API Driver Manager & Components SQL Server Driver Oracle Driver DB2 Driver Vendors develop their own drivers for access to their DBMS’s

10. 10 Lecture Objectives Client/Server Data Warehouse E-Commerce

11. 11 Data Warehouse Usually only a (very large) read-only database optimized (un-normalized) for data analysis and query processing Generally summarizes operational data into new data structures that can be accessed by decision support systems Data is extracted, transformed and summarized into new table structures

12. 12 Data Warehouse Operational data Is usually stored in a relational database – in normalized table structures Optimized to support transaction processing – daily business transactions that support a business (I.e. sales, banking)

13. 13 Data Warehouse Operational data – for example: Activity is captured in a DBMS transaction log (I.e. if a sale is made and inventory is updated) as well as an update being made to inventory to reduce it to reflect a new quantity on hand as well as to write a sales record) If the transaction fails, the transaction log is used to ‘roll back’ the inventory and sales records to the state the database was in before this particular transaction started

14. 14 Data Warehouse Types of Processing EIS – Executive Information Systems Review results of queries in pie chart, bar graph or some graphical format DSS – What If Analysis I.e. run a query and provide the ability to change a value of the data and see what the result would be (how would the data change) Drill Down – Reporting Provide results at a very high level but provide the ability to select a ‘category’ and view the results at the next level

15. 15 Data Warehouse Figure 11-15: Systems Analysis & Design in a Changing World; Course Technology Executive Information Systems

16. 16 Data Warehouse Decision Support Systems

17. 17 Data Warehouse Figure 11-14: Systems Analysis & Design in a Changing World; Course Technology Drill Down

18. 18 Lecture Objectives Client/Server Data Warehouse E-Commerce

19. 19 E-Commerce Two types of applications: B2B – Business To Business B2C – Business To Consumer Two main features of e-commerce applications: Online payments Online selection of products

20. 20 E-Commerce Uses the internet to perform business (buy, sell, trade products and services) Adds value to an organization (visibility for the company due to wide audience the internet can serve) Database design for E-Commerce uses the same concepts as if designing for a DDBMS or client/server with a few exceptions…..

21. 21 E-Commerce Database Design considerations: As you are dealing with a broad customer base, additional tables may be required to support the application (I.e. shopping cart, method of shipments, method of payments, and tax rates) Credit card and password data should be encrypted

22. 22 E-Commerce Common e-commerce Scenario: 1. A customer orders products online, entering order and credit card information on a merchant’s web page 2. The information travels from the customer’s computer over the Internet to the merchant’s web server 3. The merchant uses a third-party company to process payment authorization

23. 23 E-Commerce Common e-commerce Scenario: 4. The payment processing company contacts the customer’s credit card issuing company to authorize the transaction 5. The customer’s credit card issuer authorizes the transaction 6. The merchant receives authorization, stores the order and payment data in a database, and sends order confirmation to customer

24. 24 E-Commerce Common e-commerce Scenario: 7. The seller uses a third-party shipping company to deliver the products 8. The customer receives order and shipping information

25. 25 E-Commerce Common Production tables to support e- commerce application: CUSTOMER – contains detailed information about each registered customer PRODUCT – contains product details PRODUCT TYPE – used to group product by type so that searching is easier ORDER – contains order information ORDER LINE – contains the products selected for an order

26. 26 E-Commerce Common Support tables to support e-commerce application: SHOPCART – a temporary table which contains the products and quantity of products requested PAYMENT TYPE – a list of payment options offered by the merchant SHIPMENT TYPE – a list of shipping options offered by the merchant TAX RATE – the tax rate (by province, countries etc) PROVINCE/COUNTRY – the list of provinces/states PROMOTION – special promotion information and sales discounts PRICING – use to manage pricing levels (I.e. multiple discounts)