Frequent Itemset Mining (FIM) is a key component of many algorithms that extract patterns from transactional databases. For example, FIM can be leveraged to produce association rules, clusters, classifiers or contrast sets. This capability provides a strategic resource for decision support, and is most commonly used for market basket analysis. One challenge for frequent itemset mining is the potentially huge number of extracted patterns, which can eclipse the original database in size. In addition to increasing the cost of mining, this makes it more difficult for users to find the valuable patterns. Introducing constraints to the mining process helps mitigate both issues. Decision makers can restrict discovered patterns according to specified rules. By applying these restrictions as early as possible, the cost of mining can be constrained. For example, users may be interested in purchases whose total price exceeds $100, or whose items cost between $50 and $100. In cases of extremely large data sets, pushing constraints sequentially is not enough and parallelization becomes a must. However, specific design is needed to achieve sizes never reported before in the literature.