10. The system of claim 9 , wherein the step of counting each occurrence of each item or event in each data entry in the dataset comprises the step of: generating a count array comprising a first column including a plurality of identifiers, each identifier identifying an item or event in the dataset, and a second column comprising a plurality of counts, each count indicating a number of occurrences of an item or event identified by a corresponding identifier.
10. The system of claim 9 , wherein the step of counting each occurrence of each item or event in each data entry in the dataset comprises the step of: generating a count array comprising a first column including a plurality of identifiers, each identifier identifying an item or event in the dataset, and a second column comprising a plurality of counts, each count indicating a number of occurrences of an item or event identified by a corresponding identifier. 14. The system of claim 10 , wherein the step of determining frequent itemsets comprises the steps of: generating an array of counts of occurrences of multiple types of items or events in the same data entry.