You're building a SaaS product for 5000 tenants. Each tenant has different data (orders, customers, products). Which database isolation model do you use?

Shared Database, Shared Schema with Row-Level Security for 5000 tenants. Rationale: Separate DB (5000 databases) = impossible to manage, hugely expensive. Separate Schema (5000 schemas) = planner overhead, connection pool complexity. Shared Schema = single manageable database, cost-effective, RLS enforces isolation. Implementation: 1) Add UUID tenant_id to every table. 2) CREATE INDEX on (tenant_i