Database Migrations FAQs

Question 1

Does it support rollback procedures?

Accepted Answer

Absolutely. The skill enforces a core principle that migrations must be reversible, providing checklists for both 'UP' and 'DOWN' migration scripts.

Question 2

How does it ensure zero downtime during migrations?

Accepted Answer

It utilizes the 'expand-contract' pattern, which involves adding new columns as nullable, backfilling data, and only dropping old columns after application code has been fully updated.

Question 3

What databases does this skill support?

Accepted Answer

It primarily supports PostgreSQL and MySQL, providing specific implementation patterns for popular tools like Prisma, Drizzle, Django, and golang-migrate.

Question 4

Can it help with large-scale data updates?

Accepted Answer

Yes, it includes advanced patterns for batch data migrations that avoid full table locks by processing updates in small, committed chunks with progress tracking.

Question 5

Why shouldn't I add a NOT NULL column directly to a large table?

Accepted Answer

Adding a NOT NULL constraint without a default on an existing table requires a full table rewrite and lock. This skill teaches safe alternatives like adding nullable columns first.

Database Migrations

주요 기능

사용 사례

Database Migrations

주요 기능

사용 사례