This document discusses the application of PostgreSQL in a large social infrastructure project involving smart meter management. It describes three main missions: (1) loading 10 million datasets within 10 minutes, (2) saving data for 24 months, and (3) stabilizing performance for large scale SELECT statements. Various optimizations are discussed to achieve these missions, including data modeling, performance tuning, reducing data size, and controlling execution plans. The results showed that all three missions were successfully completed by applying PostgreSQL expertise and customizing it for the large-scale requirements of the project.