Abstract: A method for determining data structure by analyzing an outer join protocol statement used to access the data by sequentially parsing, identifying and storing each token on a push-pop stack. These steps are repeated until a join condition token is identified. The top three data are popped from the push-pop stack and represent a right database root structural node token, a join type token (left or right), and a left database structural root node token. The right and left node structures represented by the popped root node data are linked into one structure using the join type specification and the structural node points specified by the current join condition token. A root node datum representative of the resulting node structure is pushed back onto the push-pop stack. When all tokens have been processed, the node data represented by the resulting root node on the push-pop stack is ordered in accordance with the contained hierarchial data.