Acyclic Join Dependencies (AJD) play a crucial role in database design and normalization. In this paper, we use Formal Concept Analysis (FCA) to characterize a set of AJDs that hold in a given dataset. This present work simplifies and generalizes the characterization of Multivalued Dependencies with FCA.

Multivalued dependencies (MVD) and join dependencies were introduced to study database design problems. Join dependencies can be divided into cyclic and acyclic join dependencies. A fundamental result in dependency theory is that a join Dependency is acyclic if and only if it is equivalent to a set of MVDs. In addition to this characterization it has been shown that such a set of MVDs has a cov...

Abstract: The wheel graph is the join of a single vertex and a cycle, while the fan graph is the join of a single vertex and a path. The resistance distance between any two vertices of a wheel and a fan are obtained. The resistances are related to Fibonacci numbers and generalized Fibonacci numbers. The derivation is based on evaluating determinants of submatrices of the Laplacian matrix. A com...

Let G be a graph and T be a vertex subset of G with even cardinality. A T -join of G is a subset J of edges such that a vertex of G is incident with an odd number of edges in J if and only if the vertex belongs to T . Minimum T -joins have many applications in combinatorial optimizations. In this paper, we show that a minimum T -join of a connected graph G has at most |E(G)| − 1 2 |E( Ĝ )| edge...

References [1] Leonidas Fegaras. A new heuristic for optimizing large queries. [2] Toshihide Ibaraki and Tiko Kameda. On the optimal nesting order for computing n-relational joins. Optimizing large join queries using a graph-based approach. [5] Guido Moerkotte and Thomas Neumann. Analysis of two existing and one new dynamic programming algorithm for the generation of optimal bushy join trees wi...

Increasing amount of RDF data on the Web drives the need for its efficient and effective management. In this light, numerous researchers have proposed to use RDBMSs to store and query RDF annotations using the SQL and SPARQL query languages. The first few attempts at SPARQL-to-SQL translation revealed non-trivial challenges related to correctness and efficiency of such translation in the presen...

A sound and complete formal system for full acyclic join dependencies is obtained by adding three derivation rules to the axioms of multivalued dependencies. 0 1998 Elsevier Science B.V. All rights reserved.

The cyclicity of a hypergraph is an e ciently computable integer that extends the notion of the cyclomatic number of a graph The formula for the cyclicity is suggested by the join invariant of an acyclic hypergraph which is the multiset of all joining sets in any of its join trees Once we gure out how the multiplicity of a joining set depends on the structure of the acyclic hypergraph we de ne ...

In this paper we study the positive definiteness of meet and join matrices using a novel approach. When the set Sn is meet closed, we give a sufficient and necessary condition for the positive definiteness of the matrix (Sn)f . From this condition we obtain some sufficient conditions for positive definiteness as corollaries. We also use graph theory and show that by making some graph theoretic ...

When we integrate information sources that are managed locally, the integrated objects are often semistructured, since di erent sets of information sources participate in forming each of the objects. Such integration requires outer join and conversion operators: outer join operators prevent information loss that would be caused by inner joins, and conversion operators are used to mediate the in...