Visualise EXPLAIN

Turn SQL EXPLAIN output into a readable plan tree with costs and row estimates.

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ToolEXPLAIN Visualizer
Input
Output
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Preview

How it works

Plan text is parsed into nested scans, joins, sorts, aggregates, costs, estimated rows, and optional actual timing nodes. Indentation and parent-child relationships become visual tree levels.

  • Estimated plans avoid executing the query.
  • Actual timings require EXPLAIN ANALYZE.

Worked example

PostgreSQL JSON EXPLAIN
Visualize a PostgreSQL query execution plan from JSON format output
Input
											[{"Plan":{"Node Type":"Seq Scan","Relation Name":"users","Startup Cost":0.00,"Total Cost":35.50,"Plan Rows":2550,"Plan Width":36,"Filter":"(active = true)"}}]
Output
												Seq Scan (on users; Filter: (active = true)) [cost=0..35.5] [rows=2550]

When to use this

Slow-query investigations, DBA index reviews, and performance reports visualize plans.

Edge cases

  • Stale statistics can make estimated rows inaccurate.
  • EXPLAIN ANALYZE executes the statement and can cause write side effects.
  • A plan from one data distribution may not generalize.

References