This paper investigates ultrafilters in the context of connectivity systems, defined as pairs (X,
f) where X is a finite set and f is a symmetric submodular function. Ultrafilters, essential in …

In the database context, the hypertree decomposition method is used for query optimization,
whereby conjunctive queries having a low degree of cyclicity can be recognized and …

Graph theory, a fundamental branch of mathematics, centers on the study of networks
composed of vertices (nodes) and edges, examining their paths, structures, and properties …

Joins are expensive, especially on large data and/or multiple relations. One promising
approach in mitigating their high costs is to just return a simple random sample of the full join …

We study the problem of finding and monitoring fixed-size subgraphs in a continually
changing large-scale graph. We present the first approach that (i) performs worst-case …

Recent years have seen a drastic rise in the construction of web knowledge bases (eg,
Freebase, YAGO, DBPedia). These knowledge bases store structured information about real …

We study the fine-grained complexity of evaluating Boolean Conjunctive Queries and their
generalization to sum-of-product problems over an arbitrary semiring. For these problems …

We study a class of aggregate-join queries with multiple aggregation operators evaluated
over annotated relations. We show that straightforward extensions of standard multiway join …

Recently, Gottlob, Lee, Valiant, and Valiant (GLVV) presented an output size bound for join
queries with functional dependencies (FD), based on a linear program on polymatroids …

This paper is an experimental and analytical study of two classes of summary-based
cardinality estimators that use statistics about input relations and small-size joins in the …