Deleting completed transactions

AbstractWe derive necessary and sufficient conditions on when it is safe to forget (and remove) a completed transaction in several versions of conflict-graph-based schedulers. We show that the conditions can be applied repeatedly and analyze their complexity

SCUdent Books: A University-Focused Bookselling Platform

As the beginning of each university semester or quarter commences, so does the rush to acquire books for classes. The search for school books is a busy and important task for many students. However, an entire slew of problems and frustrations emerge with this academic race to gather books. To begin, students have to deal with the traditional frustrations of expensive textbooks sold at the university bookstore which is especially troublesome for those on a tight budget. Additionally, required textbooks for classes may not be available at the bookstore or require restocking which can take an unknown amount of time. Because of this, students turn to cheaper, faster, and more efficient alternatives for acquiring school books including online retailers such as Amazon or Barnes and Noble. While the Internet makes book shopping appear easier, there exist issues that come with it. Students have to put in more effort ordering online, pay for extra shipping, and wait for their books to arrive. Also, online shopping for books is incredibly decentralized with no convenient platform to cater to students\u27 needs. Students must first spend time finding out which books are required for each class and then spend even more time comparing prices from multiple online retailers. In addition, once a student completes a class he or she may no longer need the book. As a result, the student has no convenient method of disposing the book and must now sell it, throw it away, or keep it. Overall, the process of acquiring books in university is disorganized, stressful, and inconvenient for students

Change Mining in Adaptive Process Management Systems

The wide-spread adoption of process-aware information systems has resulted in a bulk of computerized information about real-world processes. This data can be utilized for process performance analysis as well as for process improvement. In this context process mining offers promising perspectives. So far, existing mining techniques have been applied to operational processes, i.e., knowledge is extracted from execution logs (process discovery), or execution logs are compared with some a-priori process model (conformance checking). However, execution logs only constitute one kind of data gathered during process enactment. In particular, adaptive processes provide additional information about process changes (e.g., ad-hoc changes of single process instances) which can be used to enable organizational learning. In this paper we present an approach for mining change logs in adaptive process management systems. The change process discovered through process mining provides an aggregated overview of all changes that happened so far. This, in turn, can serve as basis for all kinds of process improvement actions, e.g., it may trigger process redesign or better control mechanisms

A Graph Rewriting Visual Language for Database Programming

Textual database programming languages are computationally complete, but have the disadvantage of giving the user a non-intuitive view of the database information that is being manipulated. Visual languages developed in recent years have allowed naive users access to a direct representation of data, often in a graph form, but have concentrated on user interface rather than complex programming tasks. There is a need for a system which combines the advantages of both these programming methods. We describe an implementation of Spider, an experimental visual database programming language aimed at programmers. It uses a graph rewriting paradigm as a basis for a fully visual, computationally complete language. The graphs it rewrites represent the schema and instances of a database. The unique graph rewriting method used by Spider has syntactic and semantic simplicity. Its form of algorithmic expression allows complex computation to be easily represented in short programs. Furthermore, Spider has greater power than normally provided in textual systems, and we show that queries on the schema and associative queries can be performed easily and without requiring any additions to the language