Composable data sources are one of the bigger shifts in how Tableau handles data, and Kirk Munroe shows what they look like in practice. Using a bookshop sales scenario, he adds a ratings source for correlation analysis, brings in checkout data, and sets up row-level security with a Google Sheet entitlement table. He even swaps data blending for a published Excel target. If you have ever ended up with a tangle of near-identical data sources, this walks through a cleaner way to extend your analysis while keeping governance intact.