3 papers
cs.DB2025
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…
cs.DB2025
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…
cs.DB2024
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…