Review a schema change before rollout | DevPrompt Lab

A schema review prompt focused on preserving existing records and keeping application versions compatible during rollout.

Reusable content

Review the proposed schema change against current data and deployment order. Check stable identities, nullability, uniqueness scope, foreign-key deletion rules, index needs, data volume, locks, and application compatibility during a rolling deployment. Identify legacy rows that cannot map cleanly and how they remain accessible. Verify backup and restore prerequisites. Provide migration phases, reconciliation queries, and a safe rollback path. Do not recommend dropping old data until preservation is proven.

Proposal: {{PROPOSAL}}

Current data: {{CURRENT_DATA}}

Rollback plan: {{ROLLBACK_PLAN}}

How to use it

Include the database engine/version, table sizes, and a restore-tested backup reference.

Example

Phase 1 add nullable column and dual-read; phase 2 backfill deterministically; phase 3 compare counts; phase 4 switch writes; phase 5 remove legacy only in a later approved cycle.