Patent ID: 7054854

Claim:
A structured document search method for searching a structured document database, comprising: accepting a search request in the form of a logical structured document; analyzing the accepted search request to generate a search graph including graph nodes based on the logical structure, wherein the graph nodes represent one of a hierarchical-level relationship, sibling relationship, or ancestor-posterity relationship, and a variable to be embodied is inserted between the graph nodes; and generating a search plan for a hierarchical structure possessed by a searched document, in which a search processing procedure for said structured document database is developed from said search graph, said generating the search plan including: (a) applying a plan generation rule to any one of said graph nodes, using a plan generation rule base including a plurality of plan generation rules, the plurality of plan generation rules each including rule application conditions, costs and search processing procedures, the plan generation rule having a cost less than that of applicable plan generation rules of the plurality of plan generation rules and wherein the plan generation rule can be arbitrarily registered or deleted in the plan generation rule base; (b) executing a search processing procedure of the applied plan generation rule for materializing said variable; and (c) repeating the applying and the executing thereby to complete said search plan; and acquiring search results satisfying said search request by executing said search plan.