In the context of business process management, the implementation of data minimization requirements requires that analysts are able to assert what private data each worker is able to access, not only directly via the inputs of the tasks they perform in a business process, but also indirectly via the chain of tasks that lead to the production of these inputs. In this setting, this paper presents a technique which, given a workflow that transforms a set of input tables into a set of output tables via a set of inter-related SQL statements, determines what information from each input table is disclosed by each output table, and under what conditions this disclosure occurs. The result of this disclosure analysis is a summary representation of the possible computations leading from the inputs of the workflow to a given output thereof.