Multi-Tenant Student Performance Analytics Pipeline

Design a robust PostgreSQL database architecture for a multi-school learning management system that can simultaneously track student performance metrics across different educational institutions. Create a normalized schema that supports dynamic curriculum tracking, grade calculations, and cross-school comparative analytics while maintaining strict data isolation between tenants. Implement row-level security policies to ensure each school can only access its own student data, and develop a complex SQL query that can generate comparative performance reports across multiple schools without compromising data privacy.