postgresql-guide

PostgreSQL Guide

This Skill queries official PostgreSQL documentation for accurate information.

When to Use

When the user asks about or the conversation involves:

• PostgreSQL SQL syntax or commands
• Data types, functions, operators
• Database configuration (postgresql.conf, pg_hba.conf)
• Performance tuning, query optimization
• Backup, restore, high availability
• Extensions, procedural languages

Execution Steps (IMPORTANT!)

You MUST WebFetch official documentation - never answer from memory!

Step 1: Identify Question Category

Category	Description
SQL Commands	CREATE, SELECT, INSERT, UPDATE, DELETE, ALTER, etc.
Data Types	INTEGER, VARCHAR, JSON, ARRAY, etc.
Functions	String, Math, Date/Time, Aggregate, Window functions
Configuration	postgresql.conf, pg_hba.conf settings
Administration	Backup, Restore, Replication, Monitoring
Programming	PL/pgSQL, Triggers, Rules

Step 2: WebFetch the Corresponding Documentation

Base URL: https://www.postgresql.org/docs/current/

Question Type	Documentation URL
SQL Command Reference	https://www.postgresql.org/docs/current/sql-commands.html
Specific SQL Command	https://www.postgresql.org/docs/current/sql-{command}.html (e.g., sql-select.html)
Data Types	https://www.postgresql.org/docs/current/datatype.html
Functions & Operators	https://www.postgresql.org/docs/current/functions.html
String Functions	https://www.postgresql.org/docs/current/functions-string.html
Date/Time Functions	https://www.postgresql.org/docs/current/functions-datetime.html
Aggregate Functions	https://www.postgresql.org/docs/current/functions-aggregate.html
Window Functions	https://www.postgresql.org/docs/current/functions-window.html
JSON Functions	https://www.postgresql.org/docs/current/functions-json.html
Array Functions	https://www.postgresql.org/docs/current/functions-array.html
Indexes	https://www.postgresql.org/docs/current/indexes.html
Full Text Search	https://www.postgresql.org/docs/current/textsearch.html
Configuration	https://www.postgresql.org/docs/current/runtime-config.html
Authentication	https://www.postgresql.org/docs/current/auth-pg-hba-conf.html
Backup & Restore	https://www.postgresql.org/docs/current/backup.html
Replication	https://www.postgresql.org/docs/current/high-availability.html
PL/pgSQL	https://www.postgresql.org/docs/current/plpgsql.html
Triggers	https://www.postgresql.org/docs/current/triggers.html
Performance	https://www.postgresql.org/docs/current/performance-tips.html
EXPLAIN	https://www.postgresql.org/docs/current/using-explain.html
Error Codes	https://www.postgresql.org/docs/current/errcodes-appendix.html

Step 3: For Specific SQL Commands

SQL command documentation follows the pattern:

https://www.postgresql.org/docs/current/sql-{command}.html

Examples:

Command	URL
SELECT	https://www.postgresql.org/docs/current/sql-select.html
CREATE TABLE	https://www.postgresql.org/docs/current/sql-createtable.html
CREATE INDEX	https://www.postgresql.org/docs/current/sql-createindex.html
ALTER TABLE	https://www.postgresql.org/docs/current/sql-altertable.html
INSERT	https://www.postgresql.org/docs/current/sql-insert.html
UPDATE	https://www.postgresql.org/docs/current/sql-update.html
DELETE	https://www.postgresql.org/docs/current/sql-delete.html
GRANT	https://www.postgresql.org/docs/current/sql-grant.html
COPY	https://www.postgresql.org/docs/current/sql-copy.html
VACUUM	https://www.postgresql.org/docs/current/sql-vacuum.html
EXPLAIN	https://www.postgresql.org/docs/current/sql-explain.html

Step 4: Parse and Respond

Extract relevant information from WebFetch results and answer the user directly.

Common Questions Quick Reference

Question	Fetch URL
"How to create index?"	sql-createindex.html
"JSON operators?"	functions-json.html
"Window functions?"	functions-window.html
"How to backup?"	backup.html
"Connection config?"	runtime-config-connection.html
"pg_hba.conf syntax?"	auth-pg-hba-conf.html
"EXPLAIN ANALYZE?"	using-explain.html
"PL/pgSQL syntax?"	plpgsql.html

Important Reminder

Never answer PostgreSQL questions from memory!

PostgreSQL documentation is comprehensive and regularly updated. Always fetch the current documentation for:

• Exact syntax (especially for complex commands)
• Available options and parameters
• Version-specific features
• Best practices and warnings

Why not use a sub-agent?

Sub-agent responses require paraphrasing, which may cause information loss. Fetch the docs yourself for more direct and accurate information.