• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.185-192
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• 1998

A new algorithm is proposed in this paper which efficiently performs join in the temporal database. The main idea is to sort the smaller relation and to partition the larger relation, and the proposed algorithm reduces the cost of sorting the larger relation. To show the usefulness of the algorithm, the cost is analyzed with respect to the number of accesses to secondary storage and compared with that of Sort-Merge algorithm. Through the comparisons, we present and verify the conditions under which the proposed algorithm always outperforms the Sort-Merge algorithm. The comparisons show that the proposed algorithm achieves 10∼30% gain under those conditions.

• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.1
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• pp.45-52
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• 2020

This paper proposes a solution for storage and retrieval problems for Resource Description Framework (RDF) data utilizing a key-value Solid State Device (SSD), considering storage, retrieval performance, and security. We propose a two-step compression algorithm to separate logical relationship and true values from RDF data-sets using the key-value SSD. This improves not only compression and storage efficiency but also storage security. We also propose a hybrid retrieval structure based on R∗-tree to enhance retrieval efficiency and implement a sort-merge join algorithm, and discuss factors affecting R∗-tree retrieval efficiency. Finally, we show the proposed approach is superior to current compression, storage, and retrieval approaches, obtaining target results faster while requiring less space, and competitive in terms of versatility, flexibility and security.