@misc{MauererRamsauerKoelbl, author = {Mauerer, Wolfgang and Ramsauer, Ralf and K{\"o}lbl, Andreas}, title = {The Many Approaches to Real-Time and Safety-Critical Linux}, series = {Open Source Summit Japan 2017}, journal = {Open Source Summit Japan 2017}, language = {en} } @misc{BielmeierMauerer, author = {Bielmeier, Benno and Mauerer, Wolfgang}, title = {Semi-Formal Verification of Embedded Linux Systems Using Trace-Based Models}, series = {Semi-Formal Verification of Embedded Linux Systems Using Trace-Based Models}, journal = {Semi-Formal Verification of Embedded Linux Systems Using Trace-Based Models}, language = {en} } @misc{MauererWagner, author = {Mauerer, Wolfgang and Wagner, Daniel}, title = {Cyclic Tests Unleashed: Large-Scale RT Analysis with Jitterdebugger}, series = {Open Source Summit Japan (Tokio) and OSSNA 17.07.2019}, journal = {Open Source Summit Japan (Tokio) and OSSNA 17.07.2019}, language = {en} } @article{SchoenbergerScherzingerMauerer, author = {Sch{\"o}nberger, Manuel and Scherzinger, Stefanie and Mauerer, Wolfgang}, title = {Ready to Leap (by Co-Design)? Join Order Optimisation on Quantum Hardware}, series = {Proceedings of the ACM on Management of Data, PACMMOD}, volume = {1}, journal = {Proceedings of the ACM on Management of Data, PACMMOD}, number = {1}, publisher = {ACM}, address = {New York, NY,}, doi = {10.1145/3588946}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-56634}, pages = {1 -- 27}, abstract = {The prospect of achieving computational speedups by exploiting quantum phenomena makes the use of quantum processing units (QPUs) attractive for many algorithmic database problems. Query optimisation, which concerns problems that typically need to explore large search spaces, seems like an ideal match for the known quantum algorithms. We present the first quantum implementation of join ordering, which is one of the most investigated and fundamental query optimisation problems, based on a reformulation to quadratic binary unconstrained optimisation problems. We empirically characterise our method on two state-of-the-art approaches (gate-based quantum computing and quantum annealing), and identify speed-ups compared to the best know classical join ordering approaches for input sizes that can be processed with current quantum annealers. However, we also confirm that limits of early-stage technology are quickly reached. Current QPUs are classified as noisy, intermediate scale quantum computers (NISQ), and are restricted by a variety of limitations that reduce their capabilities as compared to ideal future quantum computers, which prevents us from scaling up problem dimensions and reaching practical utility. To overcome these challenges, our formulation accounts for specific QPU properties and limitations, and allows us to trade between achievable solution quality and possible problem size. In contrast to all prior work on quantum computing for query optimisation and database-related challenges, we go beyond currently available QPUs, and explicitly target the scalability limitations: Using insights gained from numerical simulations and our experimental analysis, we identify key criteria for co-designing QPUs to improve their usefulness for join ordering, and show how even relatively minor physical architectural improvements can result in substantial enhancements. Finally, we outline a path towards practical utility of custom-designed QPUs.}, language = {en} }