1. Data Management Issues in Electronic Commerce M. Tamer Özsu Department of Computing Science University of Alberta

2. Disclaimer If you are looking for answers to all your questions Get a cup of coffee and relax. I don’t have many answers.

3. What are the issues? Catalog development Intelligent querying Workflow management EC transaction atomicity Management of distribution and heterogeneity

4. Electronic Commerce Electronic commerce, in its most general definition, refers to selling and buying using electronic means. Has roots in Electronic Data Interchange (EDI) –1960’s  not new What is new? –Internet

5. Forms of Electronic Commerce Business-to-business –EDI-based –Procedures well-defined –Parties know and (generally) trust each other –Low transaction rate; high value Business-to-consumer –Internet-based –One-of-a-kind procedures –Almost no trust –High transaction rate; lower value

6. What is common? Someone has goods/services to sell Someone is looking for something to buy There has to be a mechanism for the buyer to find who sells what he/she wants There has to be a mechanism to engage in a transaction There has to be a way of exchanging money and goods/services

7. Why Databases? Many repositories –Catalogs –Working repositories Collaborative work –Sharing of repositories

8. Smart and Virtual Catalogs Smart Catalog –Searchable, annotated combinations of machine- readable (i.e., minimally processable) and machine- sensible (i.e., actually understood by computer) product data Virtual Catalog –Systems that dynamically retrieve information from multiple smart catalogs and present these product data in a unified manner with their own look and feel, not that of the smart catalog A. Keller, “Smart Catalogs and Virtual Catalogs”, In Readings in Electronic Commerce, R. Kakakota and A.B. Whinston (eds.), 1997, pp. 259-274.

9. Issues and Challenges Fully multimedia catalogs –Existing catalogs are mostly text-based virtual catalogs with embedded images –Add more support for modeling images for similarity searches –Add audio and video to provide product demonstrations, voice-overs and even commercials –Structured document databases (SGML,XML) + image databases + continuous media systems

10. Issues and Challenges More open virtual catalog environment –Single-vendor or proprietary virtual catalogs –“open” to more flexible integration of various vendor catalogs Distribution –move to the Internet environment  scalability provide search capabilities –Browsing-based access; limited search

11. Handling Document Types (DTDs) Multimedia DBMS Users DTD file DTD Parser..... DTD Manager Type Generator Query Interface DTDs Type System SGML Documents

12. Automatic Document Insertion SGML Document Instance Parse Tree.......... DTD C++ Types C++ Objects Multimedia DBMS Users Query Interface DTDs Type System SGML Documents Authoring Tools SGML Parser Instance Generator

13. EC Transactions Electronic commerce consists of processes which can be modeled as workflows. Workflow: “A collection of tasks organized to accomplish some business process.” [D. Georgakopoulos]

14. Workflow Types Human-oriented workflows Involve humans in performing the tasks. System support for collaboration and coordination; but no system-wide consistency definition System-oriented workflows Computation-intensive & specialized tasks that can be executed by a computer System support for concurrency control and recovery, automatic task execution, notification, etc. Transactional workflows In between the previous two; may involve humans, require access to heterogeneous, autonomous and/or distributed systems, ACID properties

15. Workflow Example T 1 : Search vendor catalog T 4 : Send shipping instructions T 2 :Place the order T 5 : Pay invoice T 3 :Receive proforma invoice T 6 : Receive goods T1T1 T2T2 T3T3 T4T4 T5T5 Vendor Catalog Order Database Accounts Database T6T6

16. A TOMICITY –all or nothing C ONSISTENCY –no violation of integrity constraints I SOLATION –concurrent changes invisible  serializable D URABILITY –committed updates persist ACID Properties

17. EC Transaction Atomicity “EC transaction” has a slightly different meaning –refers to the actual transaction of exchanging goods for money Atomicity of this type of transaction is important

18. Atomicity Types Money atomicity –transfer of funds from one party to another without the possibility of the creation or destruction of money –Cash transaction Goods atomicity –Money atomicity + exact transfer of goods for money –COD transactions Certified delivery –Goods atomicity + both the merchant and the customer can prove exactly what goods were delivered

19. Atomicity Protocols ready?yes/nocommit/abort?commited/aborted Phase 1Phase 2 CCC P P P P P P P P

20. NetBill CustomerMerchant NetBill Server (1) Payment order (2) PO+ invoice (3) Approval (4) Delivery of goods

21. Intelligent Querying Passive queries –“Find me all Montblanc fountain pens whose price is < $500.” Active queries –“Whenever a Montblanc fountain pen of 1920’s vintage becomes available for under $1000, let me know.” –Agent technology

22. Distributed System - Users’ Vision Distributed Catalog

23. Reality Communication Subsystem (Internet) User Query Catalog Software User Application Catalog Software Catalog Software User Query User Application Catalog Software Catalog Software

24. Issues Distribution Heterogeneity Autonomy Openness to Internet

25. If you have ideas please send me an email: ozsu@cs.ualberta.ca and watch out for the ACM SIGMOD Panel on this issue