qdtree
This visualization displays a query decision tree as a hierarchical node-link diagram. The tree structure is derived from a JSON file containing predicates, query counts, and row counts. Internal nodes show their branching predicate, while leaf nodes display their row and query statistics. The layout is computed using d3.cluster, with links drawn as horizontal paths. Node sizes are proportional to row counts, and colors indicate query performance relative to a baseline. Circles are styled with strokes to show whether data is cached, and the entire view supports zooming via d3.zoom.