A database processing system for analyzing a query issued to a database to generate a corresponding execution procedure for performing database processing in accordance therewith. A plurality of columns for storing data each constituted by a set of instances and conditions concerning the instances constituting the plurality of columns are entered. A query is inputted which contains a predicate for evaluating whether a set of instances which meet the designated conditions and which can be identified with the same subscript exists among the sets of instances stored in the plurality of columns. In response to the query, a decision is made as to whether or not an index has been generated for one or plural columns specified in the query predicate. When the index is generated, the index is accessed to acquire an identifier of table data which is “true” for a predicate. Unless the index is generated, a decision is then made as to whether or not column data acquired by accessing the database meet the conditions specified in the predicate contained in the query.