Estimated read time: 15-18 minutes The Challenge: Why Multi-Table Joins Matter at Scale When PostgreSQL runs at scale, a few expensive queries can bring down your entire service. OpenAI experienced this with ChatGPT: A single query joining 12 tables caused multiple high-severity production incidents. Complex multi-table joins are a common scaling bottleneck they can spike planning time, consume excessive resources, and create unpredictable performance. Understanding how Postg