14. A method for discovering association rules in a database using item constraints and items having a hierarchial taxonomy, the taxonomy defining descendant and ancestor relationships between the items, the method comprising: generating a set of selected items from a database based on predefined constraints, the predefined constraints involving one or more of the items in a mining input expression; determining a support value for an itemset; if the support value of the itemset is greater than a minimum support value and the itemset contains at least one of the selected items, determining the number of times the itemset appears in the database; entering the itemset into a set of large itemsets; outputting an association rule when the number of times the entered itemset appears in the database bears a predetermined relationship to a number of times an associated itemset appears in the database and thereby satisfies a minimum confidence constraint.
14. A method for discovering association rules in a database using item constraints and items having a hierarchial taxonomy, the taxonomy defining descendant and ancestor relationships between the items, the method comprising: generating a set of selected items from a database based on predefined constraints, the predefined constraints involving one or more of the items in a mining input expression; determining a support value for an itemset; if the support value of the itemset is greater than a minimum support value and the itemset contains at least one of the selected items, determining the number of times the itemset appears in the database; entering the itemset into a set of large itemsets; outputting an association rule when the number of times the entered itemset appears in the database bears a predetermined relationship to a number of times an associated itemset appears in the database and thereby satisfies a minimum confidence constraint. 19. The method recited in claim 14, the outputting association rules including pruning non-interesting association rules.