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The Expressiveness of a Family of Finite Set Languages
 IN PROCEEDINGS OF 10TH ACM SYMPOSIUM ON PRINCIPLES OF DATABASE SYSTEMS
, 1991
"... In this paper we characterise exactly the complexity of a set based database language called SRL, which presents a unified framework for queries and updates. By imposing simple syntactic restrictions on it, we are able to express exactly the classes, P and LOGSPACE. We also discuss the role of orde ..."
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Cited by 26 (3 self)
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In this paper we characterise exactly the complexity of a set based database language called SRL, which presents a unified framework for queries and updates. By imposing simple syntactic restrictions on it, we are able to express exactly the classes, P and LOGSPACE. We also discuss the role of ordering in database query languages and show that the hom operator of Machiavelli language in [OBB89] does not capture all the orderindependent properties.
Parameterized Complexity of Finding Regular Induced Subgraphs
, 2008
"... The rRegular Induced Subgraph problem asks, given a graph G and a nonnegative integer k, whether G contains an rregular induced subgraph of size at least k, that is, an induced subgraph in which every vertex has degree exactly r. In this paper we examine its parameterization kSize rRegular Induc ..."
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Cited by 8 (1 self)
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The rRegular Induced Subgraph problem asks, given a graph G and a nonnegative integer k, whether G contains an rregular induced subgraph of size at least k, that is, an induced subgraph in which every vertex has degree exactly r. In this paper we examine its parameterization kSize rRegular Induced Subgraph with k as parameter and prove that it is W[1]hard. We also examine the parameterized complexity of the dual parameterized problem, namely, the kAlmost rRegular Graph problem, which asks for a given graph G and a nonnegative integer k whether G can be made rregular by deleting at most k vertices. For this problem, we prove the existence of a problem kernel of size O(kr(r + k) 2).