Often times, we deal with large data sets. While Tableau can handle the amount of data, the source system may struggle with providing the data in one extract file. To improve upon this, it would be beneficial to provide an ability to JOIN published data sources. Although the ability to join individual extracts exists, once these are published we lose this ability to access them for use in other joins. Expanding this to published data sources would permit the acquisition of smaller individual extracts which could be published and refreshed on a schedule. These individual files could then be JOINED to create the larger, final file which itself would be refreshed from the published sources on a periodic basis.