When you partition your model, avoid partitioning on dimensions that contain alternate drill-down paths. When you specify partition level numbers in a dimension, Transformer creates partitions for the descendant categories. If you assign partition level numbers to categories in the primary drill-down path of a dimension, then drill-down performance on the categories in the alternate drill-down path may be poor. This is because the categories required for a summary value in the alternate drill-down path will have to be read from multiple partitions.