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The theme of the paper is to promote research on asynchronous transactions. We discuss our experience of executing synchronous transactions on a large distributed production system in The Boeing Company. Due to the poor performance of synchronous transactions in our environment, it motivated the exploration of asynchronous transactions as an alternate solution. This paper presents the requirements and benefits/limitations of asynchronous transactions. Open issues related to large scale deployments of asynchronous transactions are also discussed.

Clinical practice guidelines have begun to appear in electronic form with the expectation that they will be used to provide automated clinical decision support. Systems capable of executing these clinical practice guidelines are emerging concurrently. A few research projects have developed guideline authoring tools that allow encoding electronic clinical practice guidelines. However, we are not aware of tools that allow testing of electronic clinical practice guidelines by their authors. We have developed a tool called SAGEDesktop for the testing of electronic clinical practice guidelines. SAGEDesktop does not require external infrastructure to carry out this testing. It includes: 1) an embedded guideline engine which can execute electronic clinical practice guidelines 2) functionality that emulates the capabilities of a clinical information system necessary for the execution of the guideline, and 3) terminology server functionality that encapsulates standard clinical terms. Coupled with an authoring tool, SAGEDesktop provides a complete development environment in which precise and robust electronic clinical practice guidelines can be encoded and tested. We describe the features of SAGEDesktop, narrate our vision of the tool's use, and discuss SAGEDesktop's strengths and weaknesses.

This paper seeks to highlight an area important to commercial data warehouse deployments that has received limited research attention, namely, the extraction of changes to the data at the source systems. We refer to these changes as deltas. Extracting deltas from source systems is the first step in the incremental maintenance of data warehouses. A common assumption among current incremental maintenance methods is that deltas are somehow made available -normally in the form of differential files. Extraction of deltas from source systems is often not a straight forward process nor an efficient one. In this paper, we analyze how deltas can be extracted from large systems. We analyze delta extraction methods that are currently available, namely, time stamps, differential snapshots, triggers, and archive logs. We point out the strengths and weaknesses of each method through analysis and when appropriate through experimentation. We have been investigating the method called Op-Delta at Boeing that better suits delta extraction from large integrated systems. We discuss the benefits of Op-Delta, discuss how it could be implemented, and present comparative results from our experimentation.