🏷️ Tech Topics:#DatabaseQuery#EXPLAIN_ANALYZE#PostgreSQL#MySQL#QueryOptimization#SeqScan#IndexTuning
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PostgreSQL & MySQL DB EXPLAIN Plan Visualizer & Inspector Guide

Understanding database query performance requires analyzing execution plans generated by `EXPLAIN (ANALYZE, FORMAT JSON)` in PostgreSQL or `EXPLAIN FORMAT=JSON` in MySQL. Raw EXPLAIN JSON outputs are often hundreds of lines long and difficult to parse manually. This visualizer transforms raw plan JSON into an interactive node cost tree with time percentage bars and automated bottleneck detection alerts (such as Sequential Scans, Disk Temporary Spills, and high Filter Discard ratios).

✨ Key Capabilities

  • •Parses PostgreSQL EXPLAIN (ANALYZE, FORMAT JSON) and MySQL EXPLAIN FORMAT=JSON outputs.
  • •Interactive execution node tree with time percentage progress bars and cost breakdown.
  • •Automated query bottleneck detector highlighting Full Table Scans (Seq Scan) and Disk Spills.
  • •Actionable index tuning recommendations (e.g. CREATE INDEX statements).

🚀 How to Use

  1. 1Run EXPLAIN (ANALYZE, BUFFERS, FORMAT JSON) on your database query.
  2. 2Paste the JSON output into the left input panel or click Sample Plan.
  3. 3Inspect the node tree for red time-consumption bars and warnings.
  4. 4Switch to the Bottleneck Alerts tab to read index optimization recommendations.
🔒100% Client-Side Privacy Guarantee

Execution plan parsing and node tree calculations run 100% locally in your browser memory.

💡Technical Deep-Dive & Detailed FAQ Guide

1 questions & detailed answers

Q1.What is a Sequential Table Scan (Seq Scan) and why is it slow?

A Sequential Scan occurs when the database engine reads every single row in a table from disk sequentially because no matching index was available. For tables with millions of rows, this causes heavy I/O overhead and high latency.