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Networked Database Applications and Reengineering Copyright 1996 Prentice-Hall 2 Client/Server Database Client Database Program Server Database Program (Excel) (Oracle) Application Request Message Application Response Message Platform Independent Thanks to TCP Client, server can be any type of machine Network or Internet 3 Access to Multiple Databases Database Program X Server 1 Integrated Report Client Program Database Program Z Server 4 Database Program W Server 6 4 Incremental Database Development 1 Data Entry Program 2 Credit Checking Program 3 Management Statistics Program 4 Etc. Server Database Program 5 ODBC: An Application Layer Protocol Open Database Connectivity (Microsoft standard) Microsoft now pushing OLE Client Program (Application) ODBC Server Database Program (Application) Transport Layer Transport Layer Internet Layer Internet Layer Subnet Layer Subnet Layer Client Machine Server Machine 6 Database Middleware Problem: Incompatible database applications – New systems that follow different standards – Old (Legacy) systems that must be maintained One solution – Database middleware – Layer below application layer – Handles lower-layer details for application program 7 Database Middleware Incompatible Server Program Database Middleware Program Transport Internet Subnet Incompatible Legacy Program Client Program Request Response Database Middleware Program File Transfer Transport Internet Subnet Physical Layer Connection Database Middleware Program Transport Internet Subnet 8 Data Warehouse Problem: Users need data from multiple databases – They need to integrate these data – Different databases have different access methods – Queries to operational databases would cause performance problems for operational use – Queries to operational databases could cause security problems 9 Data Warehouse Solution – Extract data to a “data warehouse” – Clean up the data – Give users access and analysis tools Inventory Database Client Program Sales Database Data Warehouse Planning Database 10 Data Warehouse Tools Multidimensional databases – Can search easily by region, product, salesperson, etc. Online Analytical Processing (OLAP) – Special tools for analyzing data from databases – Forecasts, etc. Data Marts – Limited data warehouses for departments, other groups – Much easier to set up, rapid payback 11 Data Marts Large data warehouses are difficult to create and manage Data marts offer similar services for smaller groups, such as departments Simpler, easier to develop 12 Fat Client Tiers Two-Tier Processing Database Server – Server handles database access – Client handles user interface – Client may have to handle extensive calculation based on business rules. (“Extend credit if the following 20 conditions are met.) – Business rules processing can result in “fat clients” with the power normally required for servers 13 Three-Tier Processing Client only handles user interface: Thin client Business rules server handles complex calculations Database server: Retrieves appropriate data Thin Client Database Server Business Rules Server 14 On the World Wide Web Client fills out form in browser program on PC – Passes form to webserver Browser Webserver Form 15 On the World Wide Web Webserver receives the form – Passes request to a database access program Browser Webserver Database Access Program 16 On the World Wide Web Database access program formulates request – Sends to database program Database Access Program Database Program 17 On the World Wide Web Database program retrieves data – Passes to the database access program Database Access Program Database Program 18 On the World Wide Web Database Access Program Puts Answer in Webpage – Passes page to the server, which passes it to browser Browser Webserver Database Access Program 19 On the World Wide Web Interactions between the webserver and the database must be standardized CGI – Common Gateway Interface is the oldest standard – Standardizes ways of passing data values to DBMS – Standardizes ways of receiving results from DBMS, sending as webpages – Slow: each interaction restarts the DBMS program, unless proprietary APIs are used 20 On the World Wide Web Interactions between the webserver and the database must be standardized APIs – Application Program Interface – Standardized way for any application program, including webservers, to send calls to DBMSs, get responses – High-performance – Different DBMSs have different APIs – Most webservers support only some DBMS APIs 21 Distributed Databases Form 1 Replicate Update Replicate Form 2 Update 22 Distributed Databases Store data near users for rapid response Safety in case of a site disaster Replication – Propagating changes to appropriate databases – Often must be done in real time – Otherwise, two travel agents would sell the same airline seat 23 Multimedia Databases Graphics, sound, even video Telephone Directory Last name: Lee First name: Pat Extension: x6894 Click to hear Pat’s Recorded Greeting Pat’s photo will go here. 24 Commercial Online Services Provide For-Fee Information Usually Internet access too (new) User PC & Modem WAN Internal Services: Information Communication Processing Commercial Online Service The Internet 25 Commercial Online Services Consumer-Oriented Services – Focus on residential users – Widely touted in the media – America Online, CompuServe, Microsoft Network – Small part of online services business – Internet makes their future uncertain 26 Commercial Online Services Business Processing Services – Payroll – Insurance claims clearing houses, etc. – Very large Business Information Services – Credit checking, etc. – Corporate financial information – Very large 27 Commercial Online Services Electronic Data Interchange (EDI) – Business exchange high-volume business documents – Invoices – Orders, etc. – Still rather small Electronic Funds Transfer (EFT) – Send money electronically – Very large intra-bank systems 28 Reengineering If you simply automate what you are doing now, gains will be very small To get large gains – Find a more efficient way to do the end goal – You need a new strategy – Use information technology (if needed) to get you there – Good implementation is critical 29 Reengineering Importance of IT – Removes old limitations that forced us to work certain ways – But only those who can grasp new possible strategies will benefit 30 Obliterate Work Work is caused by business rules – Suppliers must furnish us with invoices Drop rules if they no longer make sense – – – – – – Ford Motor Company Suppliers now delivery goods without invoices Ford reads the Universal Product Code on boxes Ford pays automatically Slashed accounts payable department The best way to massive gains 31 Consolidate Work Bad for work to send job from one department to another in sequence – In each department, waits in line for processing – Long delays in processing – High cost because many people are involved Why send work between departments? – Before, each department had needed information in its paper files and in the heads of people 32 Consolidate Work Today – Any employee can get data from distant databases – No need to ship work between departments Case worker – Does whole task previously done by many – Like airlines reservations clerk Case teams – Where individual workers cannot do the job alone 33 Teams Form teams only as needed Get right mix of people for the job Disband the team afterward Companies may consist mostly of such teams – Ad hocracies Virtual corporations – Membership may include people outside the firm 34 Interorganizational Systems Vertical Cooperation – Manufacturer, wholesalers, or retailers may cooperate – Traditionally called the marketing system – Supplier sends goods just in time by reading buyer’s internal database system – Creates new relationships: partnerships 35 Interorganizational Systems Horizontal Cooperation – Firms that are competitors band together to offer a service – Banking ATM networks – Again, new relationships Difficult because of natural competitiveness 36 Outsourcing Decide on a firm’s core business processes – Provide firm’s sustainable competitive advantage Outsource other (non-core) business processes to another firm – Manage on a contractual basis Outsourcing firms should be less expensive – Specialization should bring economies of scale 37 New Channels Internet allows us to reach world-wide audiences – Very large audiences for massive sales – Specialized audiences reached no other way The Internet – Sell less expensively – Provide more data to customers – Route customer questions to experts – Eliminate the cost and stocking time required for traditional retailing 38 Telecommuting Spending some or all of the workday away from the office Reduces commuting time and road congestion Can provide satisfaction to telecommuters, enhancing retention But managers spend 85% of the day communicating, 55% face-to-face. – Will coordination be harmed? How can teleworkers be managed, assessed?