TRAINING A 4B MODEL TO PRODUCE 81% FASTER QUERY PLANS THAN POSTGRES

Summary from the TLDR Data newsletter

A 4B Qwen model was trained with supervised fine-tuning and reinforcement learning to generate faster PostgreSQL query plans. Across 113 join-heavy queries, its best-of-three results achieved a 1.81x geometric mean speedup over PostgreSQL's default plans and reduced total workload latency by 44.7%, showing small models can learn useful database optimization strategies from execution-time feedback.