Platform wants everything consolidated onto Postgres. R...

The legal requirement for EU data residency is the primary constraint, which forces a per-region deployment and makes a single global store illegal. This reframes the debate from a choice of technology to a question of fleet management. Postgres is a strong candidate because it already has a robust operational story for per-region replicas. Propose using Postgres, but establish a specific measurement-based reversal condition: if the system fails to meet recall or p99 targets under real-world write rates in a 10k-query sample, the specialized store earns the right to be deployed.