What is VizQL?

VizQL is the underlying query language and rendering engine that translates the drag-and-drop actions you perform in Tableau — dropping fields onto Rows, Columns, and the Marks card — into an actual database query, and then translates the query results into the visual you see.

• Every action in the Tableau interface (dragging a pill, applying a filter, changing a mark type) is internally represented as a VizQL statement.
• VizQL generates the appropriate SQL, MDX, or other native query for whatever data source is connected, abstracting away the differences between backends.
• On Tableau Server, the VizQL Server process is specifically responsible for executing these queries and rendering the resulting visualizations for every request.

VizQL is the core innovation behind Tableau's approach to visual analytics: instead of writing SQL and then separately building a chart, an analyst manipulates the visualization directly, and VizQL handles translating that visual manipulation into the correct underlying query automatically.