SQL Optimization Patterns
ynulihao/AgentSkillOS
Master SQL query optimization, indexing strategies, and EXPLAIN analysis to dramatically improve database performance and eliminate slow queries.
This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure".
Install SQL Database Assistant
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install borghei/Claude-Skills sql-database-assistant --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .claude/skills && cp -r skills-src/engineering/sql-database-assistant .claude/skills/sql-database-assistant && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .claude/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistantType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install borghei/Claude-Skills sql-database-assistant --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .agents/skills && cp -r skills-src/engineering/sql-database-assistant .agents/skills/sql-database-assistant && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .agents/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install borghei/Claude-Skills sql-database-assistant --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/engineering/sql-database-assistant .cursor/skills/sql-database-assistant && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .cursor/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/borghei/Claude-Skills.git --path engineering/sql-database-assistant--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install borghei/Claude-Skills sql-database-assistant --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/engineering/sql-database-assistant .gemini/skills/sql-database-assistant && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .gemini/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install borghei/Claude-Skills sql-database-assistantInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .github/skills && cp -r skills-src/engineering/sql-database-assistant .github/skills/sql-database-assistant && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .github/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add borghei/Claude-Skills --skill sql-database-assistant -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install borghei/Claude-Skills sql-database-assistant --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/borghei/Claude-Skills.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/engineering/sql-database-assistant .opencode/skills/sql-database-assistant && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "sql-database-assistant" agent skill from https://github.com/borghei/Claude-Skills/tree/main/engineering/sql-database-assistant into .opencode/skills/sql-database-assistant/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "sql-database-assistant", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
sql-database-assistant- GitHub stars
- 874
- Token cost
- ~1.5k tokens
- SKILL.md length
- 573 words
- Files
- 7 (incl. scripts, references)
- Skills in repo
- 364
- Repo updated
- First seen
- Licence
- MIT
At a glance
This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure".
- Works in 5 steps: Identify slow queries - Collect queries… → Analyze - Run query_optimizer.py on each… → Review findings - Prioritize by… → …
- Asks to optimize SQL queries
- SKILL.md covers Overview, Clarify First, Quick Start and Tools Overview, plus 3 more sections
- Runs Python scripts from its folder; calls python
What it does
SQL Database Assistant is an agent skill from borghei/Claude-Skills. This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure".
Its SKILL.md is about 1.5k tokens, which your agent loads only when the skill is triggered. The skill folder holds 9 other files, including scripts and reference files (for example `references/sql-optimization.md`, `scripts/migration_generator.py` and `scripts/query_optimizer.py`).
It sits in Databases, covering SQL, Query optimization and Database schema design. It works with SQL. The repository describes itself as: 385 AI skills, 77 expert agents, and 900 stdlib Python tools for every team: engineering, PM, marketing, C-level, compliance, business ops, research, and a LinkedIn toolkit… The licence is MIT.
When your agent uses it
- Asks to optimize SQL queries
- Explore database schemas
- Generate migration SQL
- Analyze query performance
Example prompts
- “optimize SQL queries”
- “explore database schemas”
- “generate migration SQL”
- “/sql-database-assistant”
Requirements
- Python 3
Workflow steps
5 steps, taken from the first numbered list in SKILL.md.
- Identify slow queries - Collect queries from slow query log
- Analyze - Run query_optimizer.py on each query
- Review findings - Prioritize by estimated impact
- Optimize - Apply suggested improvements
- Verify - Re-analyze to confirm optimization
What it can do on your machine
Read from SKILL.md and the folder at commit c9a1487. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Ships 3 files in scripts/ (Python), which the agent can run.
Shell commands in SKILL.md call:
python
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
SQL Database Assistant loads about 1.5k tokens when it runs, and up to ~2.5k if it reads all its reference files. Until then it costs about 53 tokens; SKILL.md has 573 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); the scripts in this folder are not scanned.
SKILL.md
The full file from borghei/Claude-Skills at commit c9a1487, republished under its MIT licence (© borghei). 573 words, ~1,462 tokens.
Download SKILL.mdSave it as
.claude/skills/sql-database-assistant/SKILL.md (or your agent's skills folder). This skill also uses 6 other files; get the full folder from GitHub.- name
- sql-database-assistant
- description
- This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure".
- license
- MIT + Commons Clause
- metadata.version
- 1.0.0
- metadata.author
- borghei
- metadata.category
- engineering
- metadata.domain
- databases
- metadata.updated
- 2026-04-02
- metadata.tags
- sql, database, optimization, migration, schema
SQL Database Assistant
Category: Engineering Domain: Database Development & Optimization
Overview
The SQL Database Assistant skill provides tools for analyzing SQL query performance, exploring database schemas from DDL files, and generating migration SQL from schema differences. It helps teams write efficient queries, maintain clean schemas, and manage database evolution safely.
Clarify First
Before analyzing or generating, confirm these inputs. If any is unknown or vague, ASK — do not assume:
- Task — query optimization / schema documentation / migration generation (selects the script)
- SQL input — the query, the DDL file, or the from/to schema pair to operate on (the script's actual input)
- Target database / dialect — Postgres / MySQL / etc. (changes index recommendations and migration SQL syntax)
Stop rule: ask only the 2-3 that most change the output. If the user says "just draft it," proceed and list your assumptions at the top of the artifact.
Quick Start
# Analyze a SQL query for performance issues
python scripts/query_optimizer.py --file slow_query.sql
# Analyze inline SQL
python scripts/query_optimizer.py --query "SELECT * FROM users WHERE name LIKE '%john%'"
# Explore schema from DDL file
python scripts/schema_explorer.py --file schema.sql
# Generate migration from schema diff
python scripts/migration_generator.py --from old_schema.sql --to new_schema.sql
# JSON output
python scripts/query_optimizer.py --file query.sql --format jsonTools Overview
query_optimizer.py
Analyzes SQL queries for performance issues and optimization opportunities.
| Feature | Description |
|---|---|
| SELECT * detection | Flags queries selecting all columns |
| Missing index hints | Identifies WHERE/JOIN columns likely needing indexes |
| N+1 detection | Flags correlated subquery patterns |
| Full table scan | Detects queries without WHERE clauses on large tables |
| JOIN analysis | Checks join conditions and types |
| LIKE optimization | Flags leading wildcard LIKE patterns |
schema_explorer.py
Generates documentation from SQL DDL (CREATE TABLE) files.
| Feature | Description |
|---|---|
| Table catalog | Lists all tables with column counts |
| Column details | Documents types, nullability, defaults |
| Index listing | Catalogs indexes and their columns |
| Relationship mapping | Identifies foreign key relationships |
| Markdown output | Generates schema documentation |
migration_generator.py
Generates migration SQL by comparing two schema DDL files.
| Feature | Description |
|---|---|
| Column additions | ALTER TABLE ADD COLUMN for new columns |
| Column removals | ALTER TABLE DROP COLUMN for removed columns |
| Type changes | ALTER TABLE ALTER COLUMN for type modifications |
| New tables | CREATE TABLE for entirely new tables |
| Dropped tables | DROP TABLE for removed tables |
| Index changes | CREATE/DROP INDEX for index differences |
Workflows
Query Optimization Workflow
- Identify slow queries - Collect queries from slow query log
- Analyze - Run query_optimizer.py on each query
- Review findings - Prioritize by estimated impact
- Optimize - Apply suggested improvements
- Verify - Re-analyze to confirm optimization
Show full SKILL.md (228 more words)Show less
Schema Documentation Workflow
- Export DDL - Dump schema from database
- Explore - Run schema_explorer.py to generate docs
- Review - Check relationships and data types
- Publish - Include in project documentation
Migration Workflow
- Capture current - Export current schema DDL
- Define target - Write desired schema DDL
- Generate migration - Run migration_generator.py
- Review SQL - Check generated migration for safety
- Test - Apply to staging database first
- Deploy - Apply to production with rollback plan
CI Integration
# Lint SQL queries
python scripts/query_optimizer.py --file queries/ --format json --strict
# Generate schema docs
python scripts/schema_explorer.py --file schema.sql --format markdown > SCHEMA.mdReference Documentation
- SQL Optimization - Index strategies, query patterns, anti-patterns
Common Patterns Quick Reference
Query Anti-Patterns
| Pattern | Issue | Fix |
|---|---|---|
SELECT * | Fetches unnecessary data | List specific columns |
LIKE '%term%' | Cannot use index | Use full-text search |
| Correlated subquery | N+1 query pattern | Rewrite as JOIN |
| No WHERE clause | Full table scan | Add filtering conditions |
OR in WHERE | Poor index usage | Use UNION or IN |
| Functions on indexed columns | Prevents index use | Apply to value side |
Index Guidelines
| Query Pattern | Index Type |
|---|---|
WHERE col = value | B-tree on col |
WHERE col1 = v AND col2 = v | Composite (col1, col2) |
ORDER BY col | B-tree on col |
WHERE col LIKE 'prefix%' | B-tree on col |
WHERE col IN (...) | B-tree on col |
| Full-text search | Full-text index |
Migration Safety
- Always generate rollback SQL alongside forward migration
- Test migrations against a copy of production data
- Add columns as nullable first, then backfill, then add constraints
- Never rename columns directly; add new, migrate data, drop old
© borghei, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 6 other files (scripts, references) in engineering/sql-database-assistant of borghei/Claude-Skills.
- SKILL.md
- examples/queries.sql
- examples/schema.sql
- references/sql-optimization.md
- scripts/migration_generator.py
- scripts/query_optimizer.py
- scripts/schema_explorer.py
Open the folder on GitHubat commit c9a1487
Compare with similar skills
SQL Database Assistant next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| SQL Database Assistant this skillborghei/Claude-Skills | 874 | — | ~1.5k | Automated safety check: Pass | MIT | |
| SQL Optimization Patternsynulihao/AgentSkillOS | 617 | 10 repos | ~3.3k | Automated safety check: Pass | None | |
| SQL Optimization InterviewerPrepLabsAI/InterviewMentor | 112 | — | ~2.1k | Automated safety check: Pass | MIT | |
| SQL ProJeffallan/claude-skills | 12k | — | ~1.3k | Automated safety check: Pass | MIT | |
| Discover Databaserand/cc-polymath | 181 | — | ~2k | Automated safety check: Pass | MIT | |
| Agent SQL Proxiaoyuge886/aigc | 198 | — | ~315 | Automated safety check: Pass | MIT |
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Discover Database
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Automatically discover database skills when working with SQL, PostgreSQL, MongoDB, Redis, database schema design, query optimization, migrations, connection pooling, ORMs, or database selection.
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Related
Works with
Categories
Questions about SQL Database Assistant
What does SQL Database Assistant do?
This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure". SQL Database Assistant is an agent skill from borghei/Claude-Skills. This skill should be used when the user asks to "optimize SQL queries", "explore database schemas", "generate migration SQL", "analyze query performance", or "document database structure".
When should I use SQL Database Assistant?
SQL Database Assistant fits situations like: asks to optimize SQL queries; explore database schemas; generate migration SQL; analyze query performance.
How do I install SQL Database Assistant in Claude Code?
Run `npx skills add borghei/Claude-Skills --skill sql-database-assistant -a claude-code`. Or copy the skill folder (engineering/sql-database-assistant in borghei/Claude-Skills) into .claude/skills/sql-database-assistant in your project. Claude Code loads it when a task matches its description.
How do I install SQL Database Assistant in Codex?
Run `npx skills add borghei/Claude-Skills --skill sql-database-assistant -a codex`. Or copy the skill folder (engineering/sql-database-assistant in borghei/Claude-Skills) into .agents/skills/sql-database-assistant in your project. Codex loads it when a task matches its description.
Can I use SQL Database Assistant in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add borghei/Claude-Skills --skill sql-database-assistant -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/sql-database-assistant, .gemini/skills/sql-database-assistant, .github/skills/sql-database-assistant and .opencode/skills/sql-database-assistant in your project.
What does SQL Database Assistant need to run?
Going by SKILL.md and its folder, SQL Database Assistant needs Python for the scripts in its folder and the command-line tools its instructions call (python). Our summary lists: Python 3.
Does SQL Database Assistant access the network?
SKILL.md contains no URLs. Any network use would come from the scripts or tools the agent runs. This is read from the text; nothing was executed.
Is SQL Database Assistant safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. The check reads SKILL.md only: the scripts in the folder are not scanned, so read them before running anything.
What licence does SQL Database Assistant use?
SQL Database Assistant is published under the MIT licence (declared in SKILL.md). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does SQL Database Assistant use?
About 1.5k tokens (SKILL.md is roughly 5.8k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 1k tokens, read only when the agent opens those files.
What are the alternatives to SQL Database Assistant?
Skills that share tags, products or a category with SQL Database Assistant: SQL Optimization Patterns (ynulihao/AgentSkillOS, 617 stars), SQL Optimization Interviewer (PrepLabsAI/InterviewMentor, 112 stars), SQL Pro (Jeffallan/claude-skills, 12k stars) and Discover Database (rand/cc-polymath, 181 stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains SQL Database Assistant?
borghei (a GitHub user) maintains it in borghei/Claude-Skills, which has 874 GitHub stars. The repository holds 364 skills in this directory. The repository was last updated on October 7, 2026.
Source: borghei/Claude-Skills on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.