MATHEMATICAL SUPPORT THE PROCESS OF MANAGING DIAGRAM OF RELATIONAL DATABASES IN HORIZONTAL SCALING TASKS
D.D. Gromey, E.V. Lebedenko
The article proposes an approach to the development of mathematical support system for the relational database (database control system) schematic control process, allowing to take into account the statistics of competitive access to the data query flow in the memory used by the database control system engine by hierarchy. The articles notes shortcomings of existing approaches based on the conditional costs of the query plan and the issue of ignoring the costs related to cooperative access to the data contained in a shared computer memory. There is a set-theoretic presentation of the query flow processing, which also takes into consideration the shortcomings of the existing set-theoretic models. The proposed approach ensures the actual time costs calculations for the flow of concurrently executed queries. High-level query language operations are provided through a variety of typical access operations to the In-Memory Data. The article presents a classification of the memory access operations, which allows to calculate the degree of competition during the cooperative query execution. This study also introduces a formal presentation of competitive queries and the conditions for choosing the optimal data distribution method during the database operation in a given period of time. The proposed set-theoretic model allows us to calculate the memory segments, access to which leads to a competitive query. The results obtained in this paper can be used in the development of mathematical support systems and other software for the Autonomous database control systems that automate the management of the physical database scheme.
Keywords: :database management system, query optimization, parallel data processing, competitive queries.