huiferhuifer/CloudSaver/skills/query-rewriter/SKILL.md

query-rewriter

Skill2 starsChanged 5 months agoApache-2.0View on GitHub

SQL query rewriting expert. Identifies inefficient query patterns and provides optimized alternatives. Trigger when user mentions query optimization, SQL rewriting, or query performance.

1 other project uses a version of this.

Adopted by

Most recently taken up by

SkillMedev/database-performancetheir own version, first seen Oct 5, 2026

Other versions1 project uses a version of this.
Word for word · 0
None found.
Edited · 0
None found.
Wrote their own version · 1
SkillMedev/database-performance★ 0same name
How matches are found. Word for word: the exact same text. Edited: shares passages with this file (“99% same” means 99% of its five-word phrases also appear here; 10% or more counts). Their own version: similar meaning, or, weakest, the same name. We can’t tell which project had it first. Projects are counted among the 200 most-starred candidates, and mentions are links to the repository we found, up to 50 per site, so both counts are a floor.
In this repository8 other files it gives its agents.
- cloudflare-auditSkill
- cost-audit-masterSkill
- cost-monitorSkill
- d1-cost-optimizerSkill
- index-optimizerSkill
- redis-auditSkill
- spend-cap-managerSkill
- supabase-auditSkill

The file

We split this skill into the rules it gives an agent

1 rule. About 0 are common, 1 is distinctive, and 0 are very specific to this project.

≈0
Common · estimate
Many files like this have a rule of this kind.
≈1
Distinctive · estimate
This author's own choices. Worth a look.
0
Very specific
Tied to their project's names, files or tools. Probably skip.

Common
Distinctive
Very specific

Distinctive:
Follow the specific reference file for detailed instructions.
line 43

≈ “Common” is an estimate: at least 1 in 5 of the 350,495 skill files we read have a rule of the same kind, not the same words. “Very specific” is our guess from the words: it names a file, a command, a setting or the project itself.

Keep what fits and drop the rest. Your version, ready for your agents.

Files

SKILL.md

SQL Query Rewriting Expert

Common Anti-Patterns

Anti-Pattern	Problem	Reference
SELECT *	Fetches unnecessary data	`references/select-star.md`
N+1 queries	Too many round trips	`references/n-plus-one.md`
IN with subquery	May process too many rows	`references/exists-vs-in.md`
OR across columns	Prevents index usage	`references/or-optimization.md`
OR conditions	Cannot use index	`references/union-instead-of-or.md`
Type mismatch	Implicit conversion	`references/implicit-conversion.md`

Audit Workflow

Step 1: Identify Problem Patterns

Check for:

SELECT * usage
N+1 query patterns
IN with large subqueries
OR conditions across columns
Type mismatches

Step 2: Match Anti-Pattern

Identify which anti-pattern the query matches and apply the corresponding solution from the reference file.

Step 3: Apply Rewrite

Follow the specific reference file for detailed instructions.

Step 4: Verify Improvement

EXPLAIN ANALYZE <rewritten_query>;

Benchmark Reference

Optimization	Before	After	Improvement
SELECT * → specific	100ms	20ms	80%
N+1 → batch	500ms	50ms	90%
IN → EXISTS	500ms	50ms	90%
OR → UNION	200ms	20ms	90%
Type fix	150ms	2ms	98.7%

Output Format

## Query Rewriting Report

### 1. Original Query
```sql
<original_query>

2. Anti-Patterns Detected

Pattern	Problem	Reference
...	...	...

3. Recommended Rewrite

<optimized_query>

4. Expected Improvement

Query time: Xms → Yms (Z% faster)
Rows processed: X → Y (Z% reduction)

5. Implementation

Reference: references/<case-name>.md

Download now (ZIP)

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