Starting today, you can create Amazon RDS for MariaDB, Amazon RDS for MySQL and Amazon RDS for PostgreSQL, database instances with up to 64 TiB of storage and provisioned I/O performance of up to 80,000 IOPS.

from Recent Announcements https://aws.amazon.com/about-aws/whats-new/2019/05/amazon-rds-mysql-mariadb-postgresql-64tib-support/