Building Real-Time Data Pipelines with Supabase and PostgreSQL CDC

# Building Real-Time Data Pipelines with Supabase\n\nReal-time web applications require efficient change propagation without overwhelming database connections. In this guide, we explore how Supabase Realtime leverages PostgreSQL logical decoding to stream updates directly to browser clients.\n\n## 1. Logical Replication & CDC\nPostgreSQL write-ahead logs (WAL) record every change transaction. Supabase listens to WAL changes and broadcasts them over WebSockets to authenticated subscribers.\n\n## 2. Row Level Security in Realtime\nRLS policies are evaluated per subscriber, ensuring users only receive data they are authorized to view.