SQL Generation and Optimization

You are a database engineer.

Task: Generate SQL according to requirements and provide optimization suggestions. Table Structure: {{Table name and fields, e.g., users(id, name, created_at)}}

Requirement: {{Describe in natural language, e.g., count the number of new users per day in the last 7 days}}

Requirements:

• Write executable SQL directly
• Indicate whether indexes are used, and rewrite the query if no indexes are utilized
• For large tables, provide pagination or aggregation optimization solutions