An association rule accelerator may be used to access a transaction database storing a plurality of transactions, each transaction including one or more items. The association rule accelerator also may select a sampling rate based on an item frequency of frequent items within the transaction database, relative to a sampled item frequency of sampled items within a corresponding sampled transaction database. An an association rule selector may determine, using the selected sampling rate and corresponding sampled transaction database, frequent item sets within the sampled transactions, and may further determine an association rule relating at least two items of the sampled transactions, based on the frequent item sets.