22. The method according to claim 1 , wherein there are groupings of data rows and each collection of values contains the values of a single data attribute for a single said grouping of data rows, collections of values corresponding to the same attribute being assigned with the same structure dictionary and the same methods of forming the match granules and structure granules.
24. The method according to claim 22 , wherein, for a data attribute assigned to a structure dictionary, the methods of forming a structure granule belonging to the structure dictionary include at least one of: defining an order over a domain of all possible values of said structure and including information about the minimum and the maximum values in the sub-collection of values matching said structure in said structure granule, wherein said minimum and said maximum values are derived according to said order, said order being the same for all collections of values corresponding to said attribute; an ordered list of possible values of a structure in the structure dictionary and the structure granules corresponding to said structure include information about distinct ordinal numbers of values occurring among the values matching said structure, said ordinal numbers being taken from said list of possible values, said list of possible values being the same for all collections of values corresponding to said attribute; said structure takes a form of a word built from an alphabet of symbols taking a form of constants corresponding to alpha-numeric strings and characters, and variables corresponding to generic data types including numeric, alpha-numeric and binary data types, building said word using formation rules of a formal language, representation of said structure as said word being applied to build the structure granules corresponding to said structure in the same way for all collections of values corresponding to said attribute; evaluating the candidate methods of forming the structure granules based on a group of criteria including at least one of minimizing the overall cost of creating the structure granules according to said candidate methods and maximizing the estimated efficiency of using structure granules created according to said candidate methods while resolving queries, wherein said structure granules are accessible independently from collections of values matching said structures, and said structure granules are applied to minimize the amount of accesses to said collections of values matching said corresponding structures while resolving queries, said overall cost and said estimated efficiency being measured for all collections of values corresponding to said attribute; and providing an interface to a user of the system, said interface reporting the overall cost of creating the structure granules according to said candidate methods and the estimated efficiency of using structure granules created according to said candidate methods while resolving queries, wherein said structure granules are accessible independently from collections of values matching said structures, said structure granules are applied to minimize the amount of accesses to said collections of values matching said corresponding structures while resolving queries, said user is able to add new and remove old methods of forming structure granules, said user's decisions affecting all collections of values corresponding to said attribute.