Menu

Individual skill

query-rewriter

0upvotes

Rewrites a structurally inefficient SQL query into a faster equivalent that returns identical results - correlated subqueries to joins or LATERAL, accidental cross joins to explicit ON predicates, OR-across-columns to UNION, SELECT * to projected columns, and deep OFFSET pagination to keyset. Use when a query is slow because of its shape rather than its indexes - EXPLAIN shows a Cartesian blowup, a per-row subquery, or OFFSET discarding tens of thousands of rows - and the indexes are already in place. Do NOT use when the fix is adding or reordering an index - use index-advisor instead; do NOT use to diagnose an unknown slow query from its plan - use sql-query-optimizer instead.

skills/query-rewriter/SKILL.md

Read pinned source

Source commit 97a13607d669157a4a16d5ba79b77f208319f7b9

What was checked

Matches the observed repository HEAD
Yes
Scanner rules are current
No
Repository scan complete
No
Skill scan complete
No
Observed behavior
Not checked yet
Last checked
Nov 6, 2026

These are observations at the recorded commit, not a guarantee of safety. Review the source before running it.

Install this skill

Choose an agent in your Stack or copy a command below. Commands fetch the pinned commit and copy only this skill directory. Existing destinations are refused. Copying a command does not install anything.

An install command is unavailable: current rules, complete repository and skill scans, an eligible behavior level and a permitted license are required.

Repository context

Repository stars (not skill ratings)
24
Repository last updated
Oct 13, 2026
License
MIT

Observed agent integration: No specific integration evidence. Standard SKILL.md installation does not imply verified compatibility.

Files and excerpt

File metadata and permitted, redacted excerpts come from the recorded scan. Source links are pinned to that commit.

Browse files
Read excerpt

# SQL Query Rewriter

Reshape a slow query into a faster equivalent that returns identical rows. Shape beats tuning when the query does avoidable work - but a rewrite that changes results is worse than a slow query, so equivalence is proven, never assumed. This skill owns the structural rewrite only: index choice belongs to index-advisor, and plan diagnosis belongs to sql-query-optimizer.

## Inputs to collect

1. The query text and its `EXPLAIN (ANALYZE)` output - ANALYZE if the query can be run safely, plain EXPLAIN otherwise (label conclusions from estimates as provisional).
2. Approximate row counts of each table involved, to spot Cartesian blowups.
3. The existing indexes on the touched tables - a rewrite often assumes a supporting index; confirm it exists or hand off to index-advisor.
4. What the caller actually consumes: which columns, whether order matters, whether duplicates are possible.
5. A way to run both versions against the same data for the equivalence diff.

## Workflow
Back to top