Evaluation of sampling for data mining of association rules

The discovery of association rules is a prototypical problem in data mining. The current algorithms proposed for data mining of association rules make repeated passes over the database to determine the commonly occurring item sets (or set of items). For large databases, the I/O overhead in scanning the database can be extremely high. The authors show that random sampling of transactions in the database is an effective method for finding association rules. Sampling can speed up the mining process by more than an order of magnitude by reducing I/O costs and drastically shrinking the number of transactions to be considered. They may also be able to make the sampled database resident in main-memory. Furthermore, they show that sampling can accurately represent the data patterns in the database with high confidence. They experimentally evaluate the effectiveness of sampling on different databases, and study the relationship between the performance, accuracy, and confidence of the chosen sample.