/pgfaq

name: pgfaq
description: Answer PostgreSQL core database questions by researching the local postgres source tree, PostgreSQL documentation under doc/src/sgml, relevant source code, and DeepWiki repository knowledge for postgres/postgres; use when the user asks any PostgreSQL database behavior, internals, SQL, configuration, administration, performance, storage, planner, executor, replication, or documentation question and wants a sourced Markdown answer saved to the current project's markdown directory. Refuse questions about non-PostgreSQL-core projects, including PostgreSQL ecosystem plugins, extensions maintained outside postgres/postgres, external tools, drivers, cloud services, forks, or third-party products.

pgfaq

Scope

Use this skill only for questions about the PostgreSQL core open-source project in `postgres/postgres`.

Refuse the request if it is about a project outside PostgreSQL core, including third-party extensions, plugins, tools, drivers, cloud products, forks, wrappers, or ecosystem projects. State briefly that `pgfaq` only answers PostgreSQL core questions.

Required Workflow

1. Confirm the current working directory is a PostgreSQL source checkout.

• Verify expected paths exist, especially `doc/src/sgml`.
• Prefer `git remote -v`, `git rev-parse --show-toplevel`, and directory checks when needed.
• If the current directory is not a PostgreSQL source tree, stop and ask the user to run from a postgres source checkout or provide the correct path.

2. Classify the question before researching.

• Confirm it is within PostgreSQL core scope.
• Identify likely documentation areas under `doc/src/sgml`.
• Identify likely source areas, such as `src/backend`, `src/include`, `src/bin`, `src/test`, or `contrib` only when the topic is a PostgreSQL core/contrib module shipped in the postgres repository.

3. Search local documentation and code first.

• Use `rg` for targeted searches in `doc/src/sgml` and relevant source directories.
• Read the smallest necessary source and documentation excerpts.
• Prefer primary PostgreSQL docs and code over memory.
• Capture exact file paths and line numbers for claims that matter.

4. Ask DeepWiki MCP for repository-grounded context.

• Use `mcp__deepwiki__ask_question` with `repoName: "postgres/postgres"`.
• Ask focused questions tied to the user's topic, not broad general prompts.
• Treat DeepWiki as guidance to cross-check against local code and docs, not as the sole source.

5. Synthesize the answer.

• Write in Chinese unless the user asks for another language.
• Make the answer practical and source-backed.
• Include code/doc references as local paths with line numbers when available.
• Distinguish confirmed facts from inference.
• Avoid unsupported advice, folklore, and version claims not backed by the checked source tree or docs.

6. Validate and revise before saving.

• Send the draft substance to DeepWiki MCP and ask it to check correctness against `postgres/postgres`.
• Re-check any DeepWiki correction against local docs or source code.
• Revise the answer when a correction is substantiated.
• Repeat the DeepWiki validation and local verification loop until no material correctness issues remain or remaining uncertainty is explicitly documented.

7. Save the final answer as Markdown.

• Ensure the current project has a `markdown` directory; create it if missing.
• Save the final answer under `markdown/` with a concise, filesystem-safe filename derived from the question.
• Include a short source section listing the key local docs/code files and DeepWiki checks used.
• Tell the user the saved file path.

Answer Format

Use this structure unless the user's requested format clearly conflicts:

# <question-title>

## 结论

<direct answer>

## 原理与证据

<explanation grounded in PostgreSQL docs/code>

## 实践建议

<commands, SQL examples, configuration notes, or diagnostic steps when relevant>

## 边界与版本说明

<scope, caveats, source-tree/version limitations, uncertainties>

## 参考来源

- `doc/src/sgml/...`
- `src/...`
- DeepWiki MCP: `postgres/postgres` correctness check

Research Discipline

• Use local PostgreSQL docs and source as the authority.
• Do not answer from memory when code or docs can be checked.
• Do not browse the web unless the user explicitly asks and the answer still stays within PostgreSQL core scope.
• Do not cite DeepWiki as a replacement for local evidence.
• Do not modify PostgreSQL source files while answering.
• Keep changes limited to the generated Markdown file and creating `markdown/` if needed.