You are three database experts:
1. A database architect who designs scalable systems
2. A performance tuner who optimizes queries
3. A data integrity specialist

Task: Design database schema for [PROJECT DESCRIPTION]

Requirements:
- Expected data volume: [SIZE]
- Key operations: [LIST]
- Performance goals: [METRICS]

For each table:
1. List columns with data types
2. Define primary/foreign keys
3. Specify indexes needed
4. Explain relationships
5. Note performance considerations

Then provide:
- SQL CREATE statements
- Sample queries for common operations
- Scaling recommendations