Optimization of the number of processors in the execution of nested queries

Аuthors

Brekhov O. M.^1*, Than H. M.^2**

1. Moscow Aviation Institute (National Research University), 4, Volokolamskoe shosse, Moscow, А-80, GSP-3, 125993, Russia
2. Defence services academy, Pyin OO Lwin, Republic of the Union of Myanmar

*e-mail: obrekhov@mail.ru
**e-mail: hlaing82@gmail.com

Abstract

In [3] a plan is proposed to optimize nested-query processing time for a single-processor database.
In this paper, optimization plan to optimize nested-query processing time is developed for a multiprocessor database and the minimal processing time is determined by Theorem.
Theorem. In a multiprocessor database the minimum time of the nested-queries for ordered or unordered data tables is achieved by processing all elementary queries, forming a nested — query.
Minimum query processing time for the unordered data table of all the elementary queries in the order of elementary queries is specified by condition

is determined by the expression

Minimum query processing time for the unordered data table of all the elementary queries in the order of elementary queries is specified by condition

is determined by the expression

Where
— processing time of the i-th (i = 1 , ..., r) processor of j- elementary query,
probability of success (data correspond to a specified condition) of j- elementary query,
j = (i, 2r +1 — i, 2r + i, 4r +1 — i, 4r + i, 6r +1 — i, ... , k- i+1).
Comparative execution times nested-queries for different numbers of processors are obtained for the joint and uncooperative order processing ordered and disordered data tables with parameters corresponding arithmetic and geometric progressions.
Moreover in this paper we determine the minimum number of processors, where execution time of the nested -queries is minimal.

Keywords:

database, multiprocessor computer, nested -queries, distribution of elementary queries, optimization

References

1. Amol Deshpande, Zacchary Ives, Vijayshankar Raman Adaptive Query Processing. Foundations and Trends in Databases, 2007, vol. 1, no. 1, pp.1-140.
2. Brekhov O.M. Uspekhi sovremennoi radioelektroniki, 2012, vol. 12, no. 7, pp. 37-45.
3. Brekhov O.M., Vunna D.D., Tan Kh.M. Naukoemkie tekhnologii, 2014, vol. 15, no. 2, pp.101-106.
4. Brekhov O.M., Myo Thant Vestnik Moskovskogo aviatsionnogo instituta, 2012, vol. 19, no. 5, pp. 138-146.
5. Brekhov O.M., Than Hlaing Myint Elektronnyi zhurnal «Trudy MAI», 2014, no. 73, available at: http://www.mai.ru/science/trudy/eng/published.php?ID=48833 (accessed 25.03.2014).

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