25. The device of claim 24, wherein the current box includes a child box and the magic decorrelation process comprises the steps of: performing a feed process to provide the different source for the correlation bindings; determining whether the child box is AMQ or NMQ type; and decorrelating the correlated descendant box by performing steps comprising: if the child box is AMQ type, performing an AMQ absorb process to decorrelate the correlated descendant box using the correlation bindings obtained from the different source, and then performing the feed process to children of the child box; and if the child box is NMQ type, performing the feed process to children of the child box to provide the different source of the correlation bindings, and then performing an NMQ absorb process to decorrelate the correlated descendant box using correlation bindings from the different source.
30. The device of claim 25, wherein the child box has a parent box that comprises a decorrelation output box, said decorrelation output box having a parent that comprises a correlation input box, said decorrelation output box including a first quantifier ranging over a magic child box associated with the child box, wherein the magic child box comprises a source of the correlation bindings, and wherein the AMQ absorb process comprises the steps of: routing the correlation bindings from the magic child box to the child box and creating an output column in the child box to provide an output of the correlation bindings; substituting the first quantifier in place of the decorrelation output box as the source of the correlated descendant box's correlation bindings; and deleting natural join predicates from the decorrelation output box and the first quantifier.