db-migration

name	db-migration
description	Write safe database migration scripts with data privacy considerations using Flyway

Database Migration Skill (Data Privacy Guardian)

When to Use

Invoke when creating, reviewing, or troubleshooting database migrations.

Migration Template

-- V{NNN}__{description}.sql
-- Author: [name] | Date: [YYYY-MM-DD] | JIRA: [BANK-XXX]
-- Description: [what this migration does]
-- Rollback: V{NNN}__rollback__{description}.sql
-- Privacy Impact: [Does this add/modify PII columns?]

BEGIN;
-- DDL/DML here
COMMIT;

Data Privacy Rules

• New PII columns MUST use pgcrypto encryption
• Add data classification comment: -- CLASSIFICATION: CONFIDENTIAL
• Non-production environments: add masking function for new PII columns
• Never store full credit card numbers — tokenize

Safety Rules

• Never DROP TABLE — use soft delete (add deleted_at column)
• ALTER on large tables: use CREATE INDEX CONCURRENTLY
• Add columns as NULLABLE first, backfill, then add NOT NULL