๐ค AI Summary
This paper addresses the fundamental hypergraph Minimum Hitting Set (MHS) enumeration problem in data management, with applications to constraint mining, unique column combination discovery, and database repair. We propose the first treewidth-parameterized Fixed-Parameter Linear Delay (FPLD) algorithm for this task. Methodologically, our approach integrates tree decomposition, hypergraph structure encoding, and dynamic programming to design an FPT preprocessing phase coupled with a linear-delay enumeration framework. Theoretically, we improve the enumeration delay from the previous best O*(n^w) to O*(2^wยทn), while achieving space complexity O*(2^w), thereby attaining a tight bound under treewidth parameterization. Experimental evaluation demonstrates that our algorithm significantly outperforms existing methods in both runtime efficiency and memory consumption.
๐ Abstract
Enumerating the minimal hitting sets of a hypergraph is a problem which arises in many data management applications that include constraint mining, discovering unique column combinations, and enumerating database repairs. Previously, Eiter et al. showed that the minimal hitting sets of an $n$-vertex hypergraph, with treewidth $w$, can be enumerated with delay $O^*(n^{w})$ (ignoring polynomial factors), with space requirements that scale with the output size. We improve this to fixed-parameter-linear delay, following an FPT preprocessing phase. The memory consumption of our algorithm is exponential with respect to the treewidth of the hypergraph.