METHOD OF EFFECTIVELY PERFORMING LIMITED-UNION BASED MULTIPLE-QUERIES IN A DATABASE MANAGEMENT SYSTEM

摘要

A method for efficiently performing multi-query by using a limit union technique in a database is provided to efficiently perform a technique for dividing, arranging, and selecting result tuples of the multi-query by explaining priority among feature tables in query making. Result tuples are successively divided into a set of the tuples having the same value for more than one column from the top query of an explicit query list by using limited union-on. The tuples included in each division are arranged according to order of the query generating the tuple and a value of the column(S39). Result tuples to the specified order, which is the number of a predetermined limit value, from the top of the division are returned to the arranged tuples of each division(S41).