1. A method for generating cube metadata based on an enhanced star schema, comprising: extracting, with a processor, dimension references from a factless fact table in an enhanced star schema comprising a fact table, a plurality of dimension tables of the fact table and the factless fact table, wherein the dimension table comprises a foreign key field and a set of measure fields; wherein the factless fact table shows a corresponding relationship between the dimension references and does not contain any measure field; constructing a hierarchy reference based on the dimension references; and generating cube metadata by combining the hierarchy reference with measures obtained from the fact table and a hierarchy obtained from the dimension tables in the enhanced star schema, wherein the factless fact table is directly used, without being converted, with the fact table and the plurality of dimension tables by expanding a star schema to directly comprise the factless fact table.