Amazon RDS for MariaDB 12.3 is Here – Oracle Migration Just Got Easier
Amazon RDS now supports MariaDB 12.3, the latest Long-Term Support release, bringing Oracle TO_DATE() compatibility and native JSON validation to your database. You'll get better query performance for LEFT JOINs and RANGE partitions out of the box, plus smooth upgrade paths via Blue/Green Deployments or AWS Database Migration Service.
source: [aws/whats-new]