Database Migration Patterns FAQs

Question 1

How does this skill assist with sqlc?

Accepted Answer

It provides structured patterns for organizing SQL migration files and query definitions, ensuring that the generated Go code remains type-safe and consistent with schema changes.

Question 2

Does this skill help with large data backfills?

Accepted Answer

Yes, it includes patterns for batching data updates to prevent long-running transactions and table bloat, ensuring production stability during data migrations.

Question 3

What is the expand-contract pattern for migrations?

Accepted Answer

It is a multi-phase strategy (Expand, Migrate, Contract) that allows you to change schemas without downtime by supporting both old and new structures simultaneously during the transition.

Question 4

Why shouldn't I add NOT NULL constraints to existing tables?

Accepted Answer

Adding a NOT NULL constraint without a default on an existing large table can trigger a full table rewrite and an exclusive lock, leading to application downtime.

Question 5

Is this skill specific to PostgreSQL?

Accepted Answer

While the core safety principles apply to most SQL databases, the specific syntax and implementation patterns provided (like CREATE INDEX CONCURRENTLY) are optimized for PostgreSQL.

Database Migration Patterns

Características Principales

Casos de Uso

Database Migration Patterns

Características Principales

Casos de Uso