coder000

EXPLAIN, explained

Other tools visualize query plans for experts who already read them fluently. This one narrates yours in plain English — what your database actually did, top to bottom, which step cost the most, and what's worth fixing — with every observation linked to the tutorial that teaches it.

Free API — explain plans from your own tools

The same engine powers an open API (this page uses it too). No signup, no key — just a rate limit of 60 requests per minute per IP. Handy for CI checks that fail a build when a migration quietly turns an index scan into a full-table read.

curl

curl -X POST https://www.coder000.com/api/v1/explain-plan \
  -H "Content-Type: application/json" \
  -d '{"input": "Seq Scan on patients  (cost=0.00..1693.00 rows=412 width=68)\nFilter: (active)"}'

Response shape: { "output": "…", "notes": [...], "warnings": [...] } — output is the plain-English narrative, and each note or warning carries a change, an explanation, and a link to the tutorial behind the rule. The shape is the same across all coder000 tool APIs.

Learn to read plans yourself

This tool is training wheels — the tutorials teach you to ride without them.

Indexes, MVCC & performance Database indexes, explained The SQL Server → PostgreSQL series T-SQL → PostgreSQL translator