AWS 把 db.t3.micro 與 db.t4g.micro 都放進 free tier 了：「Amazon RDS Free Tier now includes db.t3.micro, AWS Graviton2-based db.t4g.micro instances in all commercial regions」。
Customers new to AWS in the past 12 months and who were in regions where db.t2.micro was not available can now create free tier db.t3.micro or db.t4g.micro instances for the remainder of their first 12 months.
看說明是註冊的 12 個月內有這個方案可以用，可以拿來跑一些小東西...