Systems and methods process generalized-tree-pattern queries by processing a twig query with a bottom-up computation to generate a generalized tree pattern result; encoding the generalized tree pattern results using hierarchical stacks; enumerating the generalized tree pattern result with a top-down computation; a hybrid of top-down and bottom-up computation for early result enumeration before reaching the end of document; and a more succinct encoding scheme that replaces the hierarchical stacks to further improve the performance.