Chapter 22 — Further Reading

Migration tools (💻 Developer · 🏗️ DBA)

Flyway (https://flywaydb.org/), Liquibase (https://www.liquibase.org/), Alembic (https://alembic.sqlalchemy.org/). Read the getting-started for whichever fits your stack. Alembic pairs with Chapter 30 (SQLAlchemy).
Framework migrations — Rails Active Record, Django, Laravel. Same concepts, different surface.

"Zero-downtime migrations in PostgreSQL" / "Safe database migrations" guides — the canonical expand-contract treatment (Case Study 1) and the safe-ALTER techniques.
pgroll, reshape, and similar tools — automate expand-contract for PostgreSQL.
"Common DB schema change mistakes" / strong_migrations (Rails) docs — a great checklist of dangerous operations and their safe alternatives (Case Study 2's review checklist, essentially).
PostgreSQL Docs: "Explicit Locking" and "ALTER TABLE" — which operations take which locks (the root of the lock-heavy dangers).

"Deleting/updating millions of rows without downtime" — batching strategies, lock and WAL considerations (ties to Chapters 14, 27, 28).
lock_timeout / statement_timeout docs — failing fast instead of freezing the app.

"Database migrations done right" essays — versioning, review, testing on prod-like data, rollback planning.
Infrastructure-as-code for databases — treating schema as versioned code alongside the app.

Chapter 14 — Data Definition: the ALTER/lock mechanics this chapter operationalizes.
Chapter 38 — Database Administration: backups/PITR — the rollback of last resort.
Chapter 30 — ORMs: Alembic and model-driven migrations.

Turn Mercado's schema.sql into ordered migrations with up/down files.
Plan and write an expand-contract change (rename or split a column) end to end.
Write a batched, re-runnable backfill and test it on the generate_data.sql dataset to feel the difference batching makes at scale.

Next: Chapter 23 — Indexing — Part IV begins: making queries fast.