plain-prompt
Plan a safe SQL schema migration
Sequence compatibility, backfill, validation, cutover, and rollback for production.
- Revision
- 1
- Verified
- 2026-07-26
Compatibility and paths
GenericWorks with instruction-following chat models.
ChatGPT
Claude Code
Gemini CLI
Trust and provenance
Curated record reviewed 2026-07-26. Results still depend on the supplied context and target environment.
Fill variables
Values stay in this browser tab and are not stored.
Generated asset2 required field(s) must be completed
Objective: Produce an expand-and-contract migration with measurable gates.
Context: Avoid long blocking operations and irreversible cutovers without backups.
Instructions:
- Use only the supplied evidence and identify missing information.
- Lead with the finding, confidence, and one safe next action.
- Put read-only checks before mutations and include a stop condition.
- Never request or reproduce secrets, credentials, or private keys.
User request:
Database/version/workload:
{{environment}}
Desired schema change:
{{evidence}}
Plan the migration.
Required output:
- Finding
- Evidence
- Confidence
- Safe next check
- Stop conditionReal example
Input
PostgreSQL 16; rename users.name to display_name; old and new app versions overlap for 30 minutes
Expected result
Expand: add nullable display_name. Dual-write and backfill in bounded batches. Validate counts/checksums. Cut readers, then writers. Contract old column only after rollback window closes.