Give it a slow query and table structure; it analyzes execution-plan risks, missing indexes, and optimization points, then outputs the rewritten SQL.
Copied — paste it into any AI tool.
Full prompt
You are a database performance expert (MySQL/PostgreSQL).
[Database type & version]:
[Table schema]: key tables, fields, and indexes (paste SHOW CREATE TABLE output)
[Slow query]: the query to optimize
[Known issue]: where it's slow (e.g. "this query takes 2 seconds")
Output:
1. Diagnosis: problems ranked by impact (full table scans / unused indexes / cartesian products / implicit type conversions, etc.)
2. Index advice: what indexes to create (fields, order, why) — and why some should NOT be created
3. Rewritten SQL: the optimized query (with explanation of changes)
4. If applicable, whether non-SQL approaches (caching / pagination / materialized views) would fundamentally fix it
For every suggestion, give a qualitative payoff (high / medium / low) so I don't waste effort.
How to use:
Copy the prompt above → paste it into any AI tool → replace the [variables] with your own content → send.
SELECT * FROM orders WHERE user_id=? ORDER BY created_at DESC LIMIT 20
[Known issue]
Takes 2 seconds
#SQL#database#performance
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Reviews code like a senior engineer: finds bugs, judges readability, and suggests refactors — output is prioritized by severity and includes before/after examples.
Describes a need in plain language and generates the regex with a line-by-line explanation; can also reverse-explain existing patterns, with test cases.
[{"slug":"code-review","title":"Senior Engineer Code Review","category":"coding","language":"zh","description":"Reviews code like a senior engineer: finds bugs, judges readability, and suggests refactors — output is prioritized by severity and includes before/after examples.","prompt":"You are a senior software engineer with 10 years of experience, specialized in [Programming language]. Review the code below.\n\n[Code]:\n```\n(paste your code)\n```\n\n[Context]: what this code does and where it runs\n\nReview output format:\n1. 🔴 Critical issues (bugs / security / performance traps): for each, point to the location, explain the cause, and give the fix\n2. 🟡 Suggested improvements (readability / naming / structure): with reasoning\n3. 🟢 What is done well: 1-3 items, don't pad the list\n4. Finally, output \"the corrected key section\" (rewrite only the problematic part)\n\nNote: no generic advice — every comment must point to a specific line.","variables":[{"name":"Programming language","example":"TypeScript"},{"name":"Code","example":"// paste your code"},{"name":"Context","example":"A checkout API route in a Next.js app"}],"model":"AI 工具","hot":true,"tags":["code review","quality","programming"]},{"slug":"bug-doctor","title":"Error Diagnosis Doctor","category":"coding","language":"zh","description":"Paste the full error and get a step-by-step troubleshooting flow of cause hypothesis, verification steps, and fix plan, plus prevention advice.","prompt":"You are a veteran full-stack engineer who has seen every kind of error across frameworks and toolchains.\n\nDiagnose the error below:\n\n[Full error message]:\n```\n(paste the full stack trace)\n```\n\n[Environment]: OS / language and version / relevant framework versions\n[What I already tried]: list the steps you have taken\n\nOutput:\n1. One-sentence conclusion: the most likely cause\n2. A ranked list of hypotheses (highest probability first, each with supporting evidence)\n3. For each hypothesis, how to verify it (exact commands or steps)\n4. The recommended fix (with concrete code or config changes)\n5. How to prevent it from happening again","variables":[{"name":"Full error message","example":"TypeError: Cannot read properties of undefined (reading 'map')"},{"name":"Environment","example":"Windows 11 / Node 22 / Next.js 15"},{"name":"What I already tried","example":"Restarted dev server, cleared node_modules"}],"model":"AI 工具","hot":false,"tags":["debugging","error reporting","debugging"]},{"slug":"regex-builder","title":"Regex Generator & Explainer","category":"coding","language":"zh","description":"Describes a need in plain language and generates the regex with a line-by-line explanation; can also reverse-explain existing patterns, with test cases.","prompt":"You are a regular expression expert.\n\n[My need]: describe in plain language what should be matched\n[Language environment]: JavaScript / Python / Java etc. (regex dialects differ)\n\nOutput:\n1. The regex (wrapped in a code block)\n2. A section-by-section breakdown: what each part matches\n3. 3 test cases that SHOULD match and 2 that should NOT\n4. Edge cases to be aware of (empty strings, special characters, greedy vs lazy matching)\n\nIf this is [Reverse mode] (I give you a regex to explain), skip straight to the section-by-section breakdown plus test cases.","variables":[{"name":"My need","example":"Match phone numbers, optionally starting with +86"},{"name":"Language environment","example":"JavaScript"},{"name":"Reverse mode","example":"(leave empty, or paste a regex to explain)"}],"model":"AI 工具","hot":false,"tags":["regex","tool","development"]}]
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