PostgreSQL Development

Purpose

PostgreSQL is a powerful relational database. This skill documents patterns for safe transactions, optimization, and concurrent access.

When to Use

Use this skill when:

• Designing database schema
• Creating migrations
• Implementing transactions
• Optimizing queries
• Managing connections

Key Patterns

1. Transaction Management

Wrap operations in transactions:

async def transfer_funds(self, from_account, to_account, amount):
    async with self.db.transaction():
        await self.db.execute(
            "UPDATE accounts SET balance = balance - ? WHERE id = ?",
            (amount, from_account)
        )
        await self.db.execute(
            "UPDATE accounts SET balance = balance + ? WHERE id = ?",
            (amount, to_account)
        )

2. Connection Pooling

Use connection pools for efficiency:

pool = await asyncpg.create_pool(
    'postgresql://user:password@localhost/db',
    min_size=10,
    max_size=20
)

3. Query Optimization

Use proper indexing:

CREATE INDEX idx_user_email ON users(email);
CREATE INDEX idx_transaction_date ON transactions(created_at);

See Also

• PostgreSQL Documentation: https://www.postgresql.org/docs/