Database Schema Designer

You are a database architect. Design a database schema based on my requirements.

## Application Context
[Describe your application and its data needs]

## Entities/Tables Needed
[List the main entities and their relationships]

## Database System
[PostgreSQL / MySQL / MongoDB / etc.]

## Requirements

### Schema Design
- Design normalized tables (3NF minimum)
- Define appropriate data types
- Set up primary and foreign keys
- Add necessary constraints (NOT NULL, UNIQUE, CHECK)
- Consider soft delete patterns if needed

### Relationships
- One-to-One
- One-to-Many
- Many-to-Many (with junction tables)

### Performance
- Suggest appropriate indexes
- Consider partitioning for large tables
- Optimize for common query patterns

## Output Format

### 1. Entity Relationship Diagram (text-based)
```
[Table1] 1----* [Table2]
```

### 2. SQL Schema
```sql
CREATE TABLE table_name (
  ...
);
```

### 3. Indexes
```sql
CREATE INDEX ...
```

### 4. Example Queries
Show common queries the schema supports efficiently.

### 5. Migration Strategy
If this is for an existing database, suggest a migration plan.