An Evidential Approach to Integrating Semantically Heterogeneous Distributed Databases

Author(s):  
Xin Hong ◽  
Sally McClean ◽  
Bryan Scotney ◽  
Philip Morrow

2008 ◽  
Vol 24 (1-3) ◽  
pp. 73-94 ◽  
Author(s):  
Sally McClean ◽  
Bryan Scotney ◽  
Philip Morrow ◽  
Kieran Greer


Author(s):  
Tetiana Korolova ◽  
Nadiia Demianova

The vocative function of an address being the basic one is supplemented and modified by a number of other functions actualized in communication, i.e. the phatic one (establishing and developing the contact with the addressee), the status one (reflecting the status responsibility of the communicants), the emotional and attitudinal one (characterizing the addressee and the attitude of the speaker towards the uttered information). Such modification explains the polyfunctional character of the address in communication. All units of address, just like the components of the addressing functional field, are polysemantic and polysemy comprises every type of an address. According to the communicative tasks the following functions can be stated within the vocative one: nominative (naming the addressee), deixis (identifying the addressee), vocative proper (attracting the addressee’s attention). The field model of addresses’ semantic structures allows to research standard and nonstandard vocatives. The standard addresses form the nucleus of the semantic field under research and characterize stability of their application in one of the above-mentioned functions. Nonstandard vocative lexemes (1 % of the total amount of the experimental material) can play the role of an address under certain circumstances. They form semantically heterogeneous (conditioned by a situation) group, located in the periphery area of the semantic field of addresses. The addresses that include anthroponyms form the most widely used group (64,5 % in Ukrainian and 68,1 % in French), the second place belongs to the addresses with appellatives (34,6 % and 29,9 %, correspondingly). As to the composition of appellatives in the status and role addresses they comprise 36,4 % in Ukrainian and 34,9 % in French. Attitudinal addresses reach 63 % and 65,1 %, correspondingly.



Author(s):  
Mark Newman

This chapter gives a discussion of search processes on networks. It begins with a discussion of web search, including crawlers and web ranking algorithms such as PageRank. Search in distributed databases such as peer-to-peer networks is also discussed, including simple breadth-first search style algorithms and more advanced “supernode” approaches. Finally, network navigation is discussed at some length, motivated by consideration of Milgram's letter passing experiment. Kleinberg's variant of the small-world model is introduced and it is shown that efficient navigation is possible only for certain values of the model parameters. Similar results are also derived for the hierarchical model of Watts et al.



2021 ◽  
Vol 1155 (1) ◽  
pp. 012062
Author(s):  
I Ya Lvovich ◽  
Ya E Lvovich ◽  
A P Preobrazhenskiy ◽  
Yu P Preobrazhenskiy ◽  
O N Choporov


Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 423
Author(s):  
Márk Szalay ◽  
Péter Mátray ◽  
László Toka

The stateless cloud-native design improves the elasticity and reliability of applications running in the cloud. The design decouples the life-cycle of application states from that of application instances; states are written to and read from cloud databases, and deployed close to the application code to ensure low latency bounds on state access. However, the scalability of applications brings the well-known limitations of distributed databases, in which the states are stored. In this paper, we propose a full-fledged state layer that supports the stateless cloud application design. In order to minimize the inter-host communication due to state externalization, we propose, on the one hand, a system design jointly with a data placement algorithm that places functions’ states across the hosts of a data center. On the other hand, we design a dynamic replication module that decides the proper number of copies for each state to ensure a sweet spot in short state-access time and low network traffic. We evaluate the proposed methods across realistic scenarios. We show that our solution yields state-access delays close to the optimal, and ensures fast replica placement decisions in large-scale settings.



1988 ◽  
Vol 11 (3) ◽  
pp. 241-265
Author(s):  
W. Marek ◽  
C. Rauszer

In this paper, we address the problem of query optimization in distributed databases. We show that horizontal partitions of databases, generated by products of equivalence relations, induce optimization techniques for the basic database operations (i.e., the selection, projection, and join operators). In the case of selection, our method allows for restriction of the number of blocks to be searched in the selection process and subsequent simplification of the selection formula at each block. For the natural join operation, we propose an algorithm that reduces the computation of fragments. Proofs of the correctness of our algorithms are also included.



Author(s):  
Steffen Kläbe ◽  
Kai-Uwe Sattler ◽  
Stephan Baumann

AbstractCloud data warehouse systems lower the barrier to access data analytics. These applications often lack a database administrator and integrate data from various sources, potentially leading to data not satisfying strict constraints. Automatic schema optimization in self-managing databases is difficult in these environments without prior data cleaning steps. In this paper, we focus on constraint discovery as a subtask of schema optimization. Perfect constraints might not exist in these unclean datasets due to a small set of values violating the constraints. Therefore, we introduce the concept of a generic PatchIndex structure, which handles exceptions to given constraints and enables database systems to define these approximate constraints. We apply the concept to the environment of distributed databases, providing parallel index creation approaches and optimization techniques for parallel queries using PatchIndexes. Furthermore, we describe heuristics for automatic discovery of PatchIndex candidate columns and prove the performance benefit of using PatchIndexes in our evaluation.



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