Abstract: The present invention involves a computer for implementing a complex database management system. A processor has at least one complex database with extraction software. The database extraction software is capable of creating a perspective based data model from a user selected data table of the database. A query is specified by user selection of attributes from a data table of the database. A perspective based data model is created from the user selected data base table of the database and related tables. The extraction software creates a query structure defining a plurality of paths providing a selected portion of the information in the database, which is presented to the user based on the perspective based data model. The query structure defines a plurality of paths and having a plurality of nodes, each of the nodes having a corresponding operand. A downward evaluation of the query structure is performed, proceeding from a starting object down downwardly through the paths.