code-review-graph/code-review-graph-main/skills/project-review/references/manual-review/data-migration.md

Data Migration — Manual Review Checklist

High-risk module: schema/data migration requires human confirmation.

• Migration is idempotent and re-runnable
• Forward and rollback paths both defined and tested
• Backfill is batched / resumable for large tables
• Data type / precision changes do not silently truncate
• Nullability and default changes safe for existing rows
• Migration ordering across shards / replicas is consistent
• Application deploys compatibly with both old and new schema (expand/contract)
• Irreversible operations are flagged with a documented reason