In a network element a decision apparatus has a plurality of multi-way hash tables of single size and double size associative entries. A logic pipeline extracts a search key from each of a sequence of received data items. A hash circuit applies first and second hash functions to the search key to generate first and second indices. A lookup circuit reads associative entries in the hash tables that are indicated respectively by the first and second indices, matches the search key against the associative entries in all the ways. Upon finding a match between the search key and an entry key in an indicated associative entry. A processor uses the value of the indicated associative entry to insert associative entries from a stash of associative entries into the hash tables in accordance with a single size and a double size cuckoo insertion procedure.