Techniques and articles of manufacture are provided comprising computer readable programs that, when executed on the computer, cause the computer to delete a leaf from a patricia tree having leaf keys and pattern search control blocks containing a prefix and either an end-of-trail leaf or a pointer to another of the pattern search control blocks, by placing each of the prefixes in a tree prefix table; searching for a key in the tree; searching for the key in the prefix table if the tree searching does not find the key in the tree; confirming that the key is deleted if the key is not found in the prefix table; deleting the key from one of the pattern search control blocks; and collapsing the patricia tree by eliminating the left most pattern search control block from the patricia tree if the patricia tree searching finds the key.