Justification of the quasi-optimum distribution of elementary queries in multiprocessor database
Technical cybernetics. Information technology. Computer facilities
2. Defence services academy, Pyin OO Lwin, Republic of the Union of Myanmar
Criterion for the distribution of elementary queries to processors naturally defined as receiving a minimum processing time of queries when all the processors would have completed its work at the same time , while , of course, necessary to keep the order of processing of elementary queries on each processor in accordance with the terms of [1,2].
We can apply the natural distribution of elementary queries to processors in accordance with the rule, when the i-th (i = 1 , ..., r) processor receives elementary queries with numbers i, r + i, 2r + i, 3r + i, 4r + i, 5r + i, 6r + i, ...
In  we proposed quasi-optimal distribution method , when the i-th (i = 1 , ..., r) processor receives elementary queries with numbers i, 2r +1 — i, 2r + i, 4r +1 — i, 4r + i, 6r +1 — i, 6r + i, ...
This article provides an evaluation of the effectiveness of quasi-optimal distribution method in a multiprocessor database.
We have received query execution time in a multiprocessor database for natural and quasi-optimal order of their distribution; minimum and maximum limits of time for performing queries in separate processors for natural and quasi-optimal order of distribution of elementary queries; proof of the effectiveness of the quasi-optimal distribution based on the absolute and relative decrease queries execution borders using the quasi-optimal instead of a natural distribution.
We have received a number of numerical results for execution time of the query consisting of a conjunction of elementary queries. These results confirmed the effectiveness of the quasi- optimal distribution.
Keywords:database, multiprocessor computer, queries, distribution of elementary queries, optimization
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