5 citations · 6 across the 11 of their papers we have counts for
5 papers · 1 filter
Selective Use of Yannakakis' Algorithm to Improve Query Performance: Machine Learning to the Rescue
Daniela Böhm, Georg Gottlob, Matthias Lanzinger +4
Query optimization has played a central role in database research for decades. However, more often than not, the proposed optimization techniques lead to a performance improvement…
Soft and Constrained Hypertree Width
Matthias Lanzinger, Cem Okulmus, Reinhard Pichler +2
Hypertree decompositions provide a way to evaluate Conjunctive Queries (CQs) in polynomial time, where the exponent of this polynomial is determined by the width of the decompositi…
Avoiding Materialisation for Guarded Aggregate Queries
Matthias Lanzinger, Reinhard Pichler, Alexander Selzer
Optimising queries with many joins is known to be a hard problem. The explosion of intermediate results as opposed to a much smaller final result poses a serious challenge to moder…
Structure-Guided Query Evaluation: Towards Bridging the Gap from Theory to Practice
Georg Gottlob, Matthias Lanzinger, Davide Mario Longo +3
Join queries involving many relations pose a severe challenge to today's query optimisation techniques. To some extent, this is due to the fact that these techniques do not pay suf…
Semantic Width of Conjunctive Queries and Constraint Satisfaction Problems
Georg Gottlob, Matthias Lanzinger, Reinhard Pichler
Answering Conjunctive Queries (CQs) and solving Constraint Satisfaction Problems (CSPs) are arguably among the most fundamental tasks in Computer Science. They are classical NP-com…