The increasing amounts of electronic data of all forms, produced by humans (e.g. Web pages, structured content such as Wikipedia or the blogosphere etc.) and/or automatic tools (loggers, sensors, Web services, scientific tools etc.) leads to a situation of unprecedented potential for extracting new knowledge, finding new correlations etc. Typically, such analysis is performed by using data visualization techniques, and data analysis programs, which perform potentially complex and/or time-consuming analysis on the data, enrich it with new dimensions, discover commonalities or clusters etc. An important class of visual analytics applications has to deal with dynamic data, which is continuously updated (e.g. by receiving new additions) while the analysis process is running. We propose to demonstrate ReaViz, a reactive workflow platform, conceived and deployed in close connection with a database of application and workflow-related data. ReaViz enables the declarative specification of reactive data-driven workflows, which react in well-specified ways in the event of database updates.