11. The method of claim 10, further comprising: adding global existence nodes to the accessibility graph corresponding to each of the match-set and match nodes of the accessibility graph and connecting the global existence nodes in the similar manner as the match-set and match nodes; setting a value of a first global existence node to the value of a corresponding local existence node that corresponds to a match node a match pattern corresponding to a highest level match-set node; setting a value of a second global existence node corresponding to the highest level match-set node to the value of ACC if any of the first global existence node has a value of ACC; setting values of all other global existence nodes to values of global existence nodes of a next higher level in the accessibility graph if a next higher level exists and setting values to NOT-ACC if the next higher level does not exists and the other global existence nodes does not correspond to the highest level match-set node; assigning an ACC value to a match-set node of the match-set nodes if the match-set node is connected to the highest level match-set node in the accessibility graph and if the corresponding global existence node has a value of ACC, otherwise assigning a NOT-ACC value to the match-set node; and assigning an ACC value to a match node or a match-set node that is connected below a match-set node or a match node, respectively that is assigned a value of ACC.
11. The method of claim 10, further comprising: adding global existence nodes to the accessibility graph corresponding to each of the match-set and match nodes of the accessibility graph and connecting the global existence nodes in the similar manner as the match-set and match nodes; setting a value of a first global existence node to the value of a corresponding local existence node that corresponds to a match node a match pattern corresponding to a highest level match-set node; setting a value of a second global existence node corresponding to the highest level match-set node to the value of ACC if any of the first global existence node has a value of ACC; setting values of all other global existence nodes to values of global existence nodes of a next higher level in the accessibility graph if a next higher level exists and setting values to NOT-ACC if the next higher level does not exists and the other global existence nodes does not correspond to the highest level match-set node; assigning an ACC value to a match-set node of the match-set nodes if the match-set node is connected to the highest level match-set node in the accessibility graph and if the corresponding global existence node has a value of ACC, otherwise assigning a NOT-ACC value to the match-set node; and assigning an ACC value to a match node or a match-set node that is connected below a match-set node or a match node, respectively that is assigned a value of ACC. 12. The method of claim 11, wherein the generating the final query step comprises: identifying leaf match nodes of the accessibility graph having an assigned value of ACC and whose corresponding global existence nodes have values of ACC; identifying result match nodes which are all match nodes along a path from the highest level match-set node to identified leaf match nodes; collecting parts of separated portions stored or identified by data edges of result match nodes; and selecting from the collected parts to form the final query result.