VizQL: a language for query, analysis and visualization

Conventional query languages such as SQL and MDX have limited formatting and visualization capabilities. Thus, although powerful queries can be composed, another layer of software is needed to report or present the results in a useful form to the analyst. VizQL™ is designed to fill that gap. VizQL evolved from the Polaris system at Stanford, which combined query, analysis and visualization into a single framework [1].VizQL is a formal language for describing tables, charts, graphs, maps, time series and tables of visualizations. These different types of visual representations are unified into one framework, making it easy to switch from one visual representation to another (e.g. from a list view to a cross-tab to a chart). Unlike current charting packages and like query languages, VizQL permits an unlimited number of picture expressions. Visualizations can thus be easily customized and controlled. VizQL is a declarative language. The desired picture is described; the low-level operations needed to retrieve the results, to perform analytical calculations, to map the results to a visual representation, and to render the image are generated automatically by the query analyzer. The query analyzer compiles VizQL expressions to SQL and MDX and thus VizQL can be used with relational databases and datacubes. The current implementation supports Hyperion Essbase, Microsoft SQL Server, Microsoft Analysis Services, MySQL, Oracle, as well as desktop data sources such as CSV and Excel files. This analysis phase includes many optimizations that allow large databases to be browsed interactively. VizQL enables a new generation of visual analysis tools that closely couple query, analysis and visualization.