A database integrity monitor with applications to vehicular technology

One of the challenges facing the designers of an integrated engineering sys tem is to blend in a robust and efficient way a wide variety of independent ly developed programs, each with its specific requirements for input and ou tput. The Environment for Application Software Integration and Execution (E ASIE, for short) provides a methodology and set of utility routines to supp ort building, maintaining, and applying computer-aided design systems consi sting of large numbers of diverse, stand-atone analysis codes. To support a high-productivity design and engineering environment, a tool is needed to identify potential integrity Violations introduced in the database as a res ult of activities involving manually changing the contents of some variable s, and/or the subsequent execution of a number of analysis programs on the modified data. Such activities are routinely performed by design engineers in the aerospace industry, vehicular technology, and user mobility manageme nt in cellular systems. It is therefore important to create an environment that allows the designers to perform 'what if' experiments while, at the sa me time, monitoring the integrity of the underlying database. A fundamental task of such an environment is to make the user aware of potential integri ty Violations introduced in the database as a result of any data changes. A trigger technique is described for identifying, beforehand, the set of all variables in the database susceptible to inconsistency. We offer a general solution to the integrity checking problem as defined above. Our integrity monitoring algorithms are transitive closure-based and they compare favora bly with the state of the art both in simplicity and in efficiency. To illu strate, we show how our solution can be implemented in the Environment for Application Software integration and Execution (EASIE, for short) developed at NASA Langley Research Center (LaRC). We address this problem in general , and discuss how it can be implemented in EASIE. Our integrity monitoring algorithms are transitive closure-based and they compare favorably with the state of the art both in simplicity and in efficiency.