SQL EXPLAIN Plan & Query Cost Analyzer
Analyze PostgreSQL and MySQL execution plans, detect unindexed sequential scans, and estimate query latency.
Execution runs 100% locally inside the browser sandbox using HTML5 Canvas, Web Cryptography Subtle API, and Web Workers. No data is ever transmitted across the network.
Zero network latency. Operates completely offline with zero dependencies on third-party backend servers or cloud services.
Built according to official RFC specifications, cryptographic test vectors, and enterprise-grade data transformation standards.
How to Use SQL EXPLAIN Plan & Query Cost Analyzer
Run EXPLAIN ANALYZE on your SQL database and paste the text plan.
Review detected execution nodes (Seq Scan, Index Scan, Joins) and execution latency.
Identify unindexed filter columns and optimize query predicates.
Frequently Asked Questions
What is the difference between EXPLAIN and EXPLAIN ANALYZE?
EXPLAIN shows the database query planner's estimated cost without running the query, while EXPLAIN ANALYZE actually executes the query to return real timing and row counts.
Why is a Sequential Scan dangerous on large tables?
A sequential scan reads every single disk block in the table, which causes high I/O latency and degrades database throughput without an index.
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