Vanderbilt University Medical Center, Nashville, Tennessee. One goal of the Informatics Center at Vanderbilt. University Medical Center (VUMC) is the migration.
Design Challenges for Web-Based Database Maintenance Douglas A. Talbert, M.Sc. and Antoine Geissbuhler, M.D. Informatics Center Vanderbilt University Medical Center, Nashville, Tennessee One goal of the Informatics Center at Vanderbilt technical sophistication and knowledge of how University Medical Center (VUMC) is the migration systems use the data. of data storage and maintenance from proprietary One complicating factor is that these issues often information systems to a vendor-independent external cannot be analyzed independently. For example, the environment. Benefits include easier access to the design implications associated with maintaining a data by other information systems and data mission-critical database may depend on the level of persistence that is independent of a specific vendor. users have regarding how various understanding One manner in which we are achieving this goal is systems use the data. Another difficulty is that through the use of the Web as a distributed user accurate knowledge about these design issues may be interface for maintaining locally developed relational impossible to obtain. In such situations assumptions databases. We chose to use the Web for many must be made. If constraints such as system resources reasons including user familiarity, low distribution and development time are not adversely affected, we cost, and minimal development time. The aim of our chose the assumption that would be least damaging if project is to describe some design challenges of Webit were wrong. For example, if the technical based database maintenance and how we chose to sophistication of the users is unknown, incorrectly address these challenges. assuming a high level of sophistication might be At one level, goals for any database maintenance dangerous, whereas incorrectly assuming a low level system should be the same, hiding data complexity, is probably only annoying. Adjustments would be limiting access to sensitive data, adapting easily to needed in either scenario. The latter, however, is changes in the data model, ensuring data integrity, likely to be a safer option. and providing an intuitive user interface. However, We will not attempt to examine every combination of the manner in which these goals are achieved in a data/user characteristics and assumptions, but the Web-based architecture may vary from project to table below examines these issues in the context of project. The project characteristics that influence two systems we have implemented at VUMC, these design decisions fall into two broad categories, Amanita and Portobello. We believe that our data-related issues and user-related issues. Datashed some light on decisions that will be experiences related issues include complexity, sensitivity, faced by anyone designing system of this type. stability, and criticality. User-related issues include Amanita Portobello Purpose: maintain user identification and set of user privileges Purpose: maintain the data needed to allow items (tests, prescriptions, etc ... ) to be ordered Characteristics Design implication Characteristics Design implication simple data model, high level allow direct manipulation of complex data model, little web interface submits of user knowledge about data database from web interface user knowledge about data executable scripts that a data usage, and mission-critical usage, and mission-critical librarian can use to modify data sensitive data (view and
modify) one user group oflower technical sophistication and one group ofhigher sophistication
1091-8280/99/$5.00 C
1999 AMIA, Inc.
must control access to data and maintain session context throughout web session since the different levels of sophistication coincide with different duties, provide different web interfaces to each group
data sensitive data (modification only)
the database must control access to data and maintain session context throughout web session
data model likely to evolve in currently unforeseen ways and low level of user technical sophistication
much effort put into separating data model from user interface and must scope view of data to subset appropriate for user
1177
