External optimization of SQL-query under conditions of databases structural uncertainty

The paper deals with factors that influence the speed of data receiving in information systems. The method of automatic external SQL-query optimization is described. The method is based on the principle of building a local model of controlled process. It allows one to optimize the SQL-queries regardless of applied database management system and its settings. The structural and functional diagram of adaptive system of an external SQL-query optimization is presented. Possibility of using the proposed method under the conditions of databases structural uncertainty was tested.