Visual Query Plan & Optimization Hints: Understand and Fix Queries Before They Run
The Explain view now renders your query's execution plan as a fully interactive visual graph, paired with a Plan Insights summary and Optimization Hints that point to specific problems and tell you how to fix them.
Plan Insights: the big picture in seconds
The right-hand panel gives you a structural overview of your query: total operators, tree depth, max fan-out, CTE count, exchanges, filters, aggregates, and columns read. Below that, a Join Types breakdown shows exactly how many of each join strategy the planner chose, hash joins, nested loop joins, cross products, and others, so you can spot expensive patterns immediately.
Interactive plan graph
The full execution plan renders as a zoomable, navigable tree. Each node shows its operator type (scan, filter, projection, window, CTE, aggregate), the expression or columns involved, and the estimated cardinality. Click any node to inspect it. Zoom out to see the full shape of a 100+ operator plan, or zoom in to trace a specific branch.
Optimization Hints: actionable, not generic
This is where it gets practical. Ilum analyzes the plan and surfaces concrete issues with severity indicators:
- Duplicate scan detection - flags when a table is scanned multiple times (e.g., 7×) and suggests caching or CTE restructuring to eliminate redundant reads.
- Deep plan warning - alerts when the plan tree is unusually deep, recommending you break the query into stages with temporary tables or cached CTEs.
- Each hint includes a "Go to node" link that jumps directly to the problematic operator on the graph, so you don't have to hunt through a complex plan manually.
Why it matters
Most SQL users run EXPLAIN and get a wall of text. This turns that into a visual debugging tool with built-in intelligence - you see the plan, understand the shape, and get told what to fix, all in one view. Catch redundant scans, expensive joins, and over-complex plans before they waste compute. Works with DuckDB, Trino, and Spark SQL.
Where to find it
Write your query in the SQL Editor and click Explain. The plan graph opens in the results panel with Plan Insights and Optimization Hints visible on the right.
Introduced in 6.7.0
Introduced in 6.7.0
