1. A method for processing a database modeled as an edged-labeled tree to obtain desired information, comprising: identifying at least one path of the edged-labeled tree that does not contain the desired information; and processing the database with a composite automation which includes a schema having known structure and unknown structure, to retrieve the desired information without processing the identified path of the edge-labeled tree.
2. The method of claim 1, wherein the identifying step comprises: generating an automaton based on the desired information; generating the composite automaton by combining a schema of the database with the automaton; and analyzing the composite automaton to identify broken paths.