We address the issue of applying join operation to the relational data managed in the form of multiple replicas in data grid. A join algorithm is developed that solves the problem of replica matching and execution node selection by making use of matching theory. To ease the data transference among the grid nodes, we introduce relation reduction and row blocking techniques. The analytical and ex...

We show there is a non-recursive r.e. set A such that if W is any low r.e. set, then the join W ⊕ A is also low. That is, A is “almost deep”. This answers a question of Jockusch. The almost deep degrees form an definable ideal in the r.e. degrees (with jump.)

We give two sufficient conditions for the lattice Co(Rn, X) of relatively convex sets of Rn to be join-semidistributive, where X is a finite union of segments. We also prove that every finite lower bounded lattice can be embedded into Co(Rn, X), for a suitable finite subset X of Rn.

A spatial join computes all pairs of spatial objects in two data sets satisfying a distance constraint. An increasing demand in applications ranging from human brain analysis to transportation data analysis motivates studies on designing new in-memory spatial join algorithms. Among recent proposals, the following six algorithms can efficiently perform in-memory spatial joins: Size Separation Sp...

A join-index is a data structure used for processing join queries in databases. Join-indices use precomputation techniques to speed up online query processing and are useful for data sets which are updated infrequently. The I/O cost of join computation using a join-index with limited buffer space depends primarily on the page-access sequence used to fetch the pages of the base relations. Given ...

A Join Index is a data structure used for processing join queries in databases. Join indices use pre-computation techniques to speed up online query processing and are useful for data-sets which are updated infrequently. The cost of join computation using a join-index with limited buuer space depends primarily on the page-access sequence used to fetch the pages of the base relations. Given the ...

Unit selection synthesis has improved the quality of synthetic speech by making it possible to concatenate speech from a large database to produce intelligible synthesis while preserving much of the naturalness of the original signal. Such synthesis is by no means perfect, however, and this paper describes work to achieve more optimal joins between concatenated units. Results from a psychoacous...

This paper proposes a refinement of the PS-Merge merging operator, which is an alternative merging approach that employs the notion of partial satisfiability rather than the usual distance measures. Our approach will add to PS-Merge a mechanism to deal with a kind of priority based on the quantity of information of the agents. We will refer to the new operator as Pr-Merge. We will also analyze ...