Increase the effectiveness of search databases queries using the algorithm of bitmap scales

Query optimization is an important part of any database application. The most effective method of an acceleration of search queries is use of index structures. It is known that queries which use the indexes (clustered and not clustered) are effective in the case of low percent of the repeating values in columns. If indexable data are not selective, use of the majority of types of indexes is not effective. Main objective of the performed work is extending of SQL Server MS for creation of indexes and increase in productivity of search queries. In the furtherance of this goal the high level language Net-application using C# is created. Embedded algorithm creates a bit scales for processing of relational tables columns with a large count of the duplicated values. In article it was conducted the review of the main existing methods of search query efficiency increasing and types of the index structures used in different database management systems. Examples of action of application for selection of values with use of bit indexes are shown. Testing of the created software product on tables with different cardinality allows to draw conclusions about the considerable abbreviation of time of data handling in case of using of bit indexes in comparison with other search algorithms.