database-migrationlisted

Use when planning or applying a raw-SQL database migration to a live PostgreSQL database — adding columns, renaming columns or tables, changing types, creating indexes, adding foreign keys, or running data backfills. Covers zero-downtime patterns (expand / contract, batched backfill, NOT VALID foreign keys, CONCURRENTLY indexes), the unpooled-connection requirement for DDL, branched-database workflows, and rollback strategy. Do NOT use for ORM-managed migrations driven by Prisma/Drizzle/TypeORM CLI scaffolding (the generation rules are tool-specific), for chasing a migration that has already failed in production (use `debugging`), or for designing the row-level-security model itself (use `owasp-security`).
jacob-balslev/skill-graph · ★ 0 · API & Backend · score 66

Install: claude install-skill jacob-balslev/skill-graph

# Database Migration ## Coverage - Migration file conventions: chronological filenames, headers documenting purpose and rollback, `BEGIN/COMMIT` framing, when DDL must escape the transaction - Connection requirements: why DDL needs an unpooled connection (PgBouncer transaction-mode rejects DDL session state), and the two-URL pattern for live applications - Branched-database workflow: create a branch, apply migration, schema-diff against parent, apply to main, prune the branch — with a vendor-capability matrix - Common DDL patterns: nullable column, column with constant default, column with non-constant default on a large table (batched backfill), zero-downtime rename via expand / contract, type change via shadow column, concurrent index creation, low-lock foreign key (NOT VALID + VALIDATE) - Tenant-scoped schema additions: how to keep multi-tenant isolation safe across migrations (RLS-policy-in-migration discipline), without owning the policy design itself - Zero-downtime table rename: compatibility view pattern that lets old code keep reading while the new name takes over - Rollback strategy: transactional rollback for structural changes, `DOWN` paths for non-transactional ones, point-in-time restore as the last resort - Pre-production checklist: schema diff, branch test run, NOT VALID gating, CONCURRENTLY gating, RLS gating, rollback documented in header ## Philosophy A migration is the only operation in the application stack that is *both* shipped as code *and* irrever