Dave Catherman BSEE /CS 1979 U. of Idaho 9 years in U.S. Navy Helicopter Pilot Computer Systems Manager 4 years at Honeywell Inc. Quality Engineer Application Developer 4.5 years at JAARS Technology Evaluator Database Application Design 4/12/2019
JAARS Technical Support for Wycliffe Bible Translators Aviation Support Telecommunications Construction and Maintenance Purchasing and Shipping Material Transportation Computing 4/12/2019
International Computers Services (ICS) provides services in: Buying computers and software Training on how to use the PC Software development Access to linguistics applications Repair and maintenance User support services Networking and E-mail Adapting the latest technology 4/12/2019
Systems Engineering Department Technology Evaluator Evaluate new technology - write reports God can use technology to speed evangelization Database Application Development International database coordinator Design/develop database applications for field Teach Microsoft Access classes 4/12/2019
Harnessing Distributed Database Technology Overview: The Problem Possible Solutions Our Situation 4/12/2019
The Problem: Collecting the Information Data is located in the field offices No on-line communication Require reports to be submitted Re-key the reports into system Fields have no automated systems standard Each administration develops own system No standard way to submit electronically 4/12/2019
The Problem: Distributing the Information Decision makers are in the field Projects depend on analysis of the data Personnel need advanced notification No on-line means of querying data Most field sites don’t have Internet yet Printed reports lack flexibility CD-ROM distribution too slow 4/12/2019
The Solution: Distributed Databases/Replication Duplicate copy of database in each location Updates are replicated to and from each copy Usually requires a network connection Available now in most database servers Oracle/Sybase/Informix/SQL Server Most fields don’t have server capability Most fields don’t have Internet connection 4/12/2019
The Recommendation: Microsoft Access 97 PC based database (on Windows 95/NT) Fully relational development environment Good Rapid Application Development Supports direct and indirect replication Has partial replication capability Replication is record based 4/12/2019
The Goal: Partial Replication - User Security Master database located at home office Partial replication for each field site feature of MS Access 97 User/group level security for each user Restricted views for general querying Encrypted links for sensitive locations Code names used for sensitive projects 4/12/2019
The Strategy: Indirect Replication over E-mail Indirect synchronization Can be scheduled or on demand Places updates file in a dropbox directory Use E-mail as transport mechanism MAPI process to attach file to a message Normal E-mail delivery to destination MAPI process to detach file in dropbox Updates picked up by Synchronizer 4/12/2019
Issues and Problems: Upgrading PCs to support Windows 95 Program control of the updates and dropbox Personnel for conflict resolution Conflict results from two sites updating the same record Process or person must resolve conflict Size of database and update files 4/12/2019
Other Possible Solutions: Wait until all fields have Internet Write our own replication system Continue to look for other vendor solutions 4/12/2019
Questions and Comments 4/12/2019