64 citations · 362 across the 43 of their papers we have counts for
5 papers · 1 filter
Tractable Orders for Direct Access to Ranked Answers of Conjunctive Queries
Nofar Carmeli, Nikolaos Tziavelis, Wolfgang Gatterbauer +2
We study the question of when we can provide direct access to the k-th answer to a Conjunctive Query (CQ) according to a specified order over the answers in time logarithmic in the…
Optimal Join Algorithms Meet Top-k
Nikolaos Tziavelis, Wolfgang Gatterbauer, Mirek Riedewald
Top-k queries have been studied intensively in the database community and they are an important means to reduce query cost when only the "best" or "most interesting" results are ne…
QueryVis: Logic-based diagrams help users understand complicated SQL queries faster
Aristotelis Leventidis, Jiahui Zhang, Cody Dunne +3
Understanding the meaning of existing SQL queries is critical for code maintenance and reuse. Yet SQL can be hard to read, even for expert users or the original creator of a query.…
Near-Optimal Distributed Band-Joins through Recursive Partitioning
Rundong Li, Wolfgang Gatterbauer, Mirek Riedewald
We consider running-time optimization for band-joins in a distributed system, e.g., the cloud. To balance load across worker machines, input has to be partitioned, which causes dup…
Factorized Graph Representations for Semi-Supervised Learning from Sparse Data
Krishna Kumar P., Paul Langton, Wolfgang Gatterbauer
The paper introduces a scalable method that estimates class compatibility matrices directly from extremely sparsely labeled graphs using factorized graph representations, enabling…