db-review

When this skill is invoked:

1. Read the target schema, migration, or query files in full.

2. Evaluate schema design:

   • All tables have a primary key
   • Tables have created_at and updated_at columns
   • Foreign key relationships defined with proper constraints
   • Column types are appropriate (don't use VARCHAR(255) for everything)
   • NULL vs NOT NULL is intentionally chosen and documented
   • Enum types used for fixed sets of values

3. Evaluate indexing strategy:

   • Every foreign key column is indexed
   • Columns in frequent WHERE, ORDER BY, or JOIN conditions are indexed
   • Composite indexes match the query patterns
   • No over-indexing (too many indexes slow writes)
   • Unique constraints used where business rules require uniqueness

4. Evaluate migration safety:

   • Migration is reversible (has a down/rollback script)
   • Adding columns with defaults is safe for zero-downtime
   • Removing columns uses soft-delete / multi-phase approach
   • Renaming columns uses multi-phase migration (add → backfill → drop old)
   • Large table operations consider locking implications

5. Evaluate data integrity:

   • Check constraints for value ranges where appropriate
   • No orphaned records possible (foreign keys or enforced at app layer)
   • Soft delete implemented (deleted_at) not hard delete for important records

6. Evaluate query quality (if queries provided):

   • No SELECT * in application queries
   • N+1 queries avoided (eager loading where needed)
   • Parameterized queries (no string concatenation)
   • Pagination on all list queries

7. Output the review:

## Database Review: [Schema/Migration Name]

### Schema Design: [CLEAN / ISSUES FOUND]
[List design problems]

### Indexes: [APPROPRIATE / MISSING / OVER-INDEXED]
[List index recommendations]

### Migration Safety: [SAFE / RISKY / BLOCKING]
[List migration risks and recommendations]

### Data Integrity: [ENFORCED / GAPS FOUND]
[List integrity concerns]

### Query Quality: [CLEAN / ISSUES FOUND]
[List query problems]

### Positive Observations
[What is well-designed]

### Required Changes
[Must-fix before applying]

### Suggestions
[Nice-to-have improvements]

### Verdict: [APPROVED / APPROVED WITH SUGGESTIONS / CHANGES REQUIRED]

Protocol

• Question: Auto-starts from argument (schema, migration, or query files)
• Options: Skip — single review path
• Decision: Skip — verdict is advisory
• Draft: Full review shown in conversation only
• Approval: Skip — read-only; no files written