Amazon RDS for Oracle Gives You Control Over Minor Version Upgrades
Amazon RDS for Oracle now lets you disable automatic minor version upgrades for DB instances using JVM, Spatial, Locator, or OLAP options—giving you full control over when patches roll out. This flexibility is available across all commercial AWS Regions and AWS GovCloud (US), so you can manage your upgrade schedule without losing security benefits.
source: [aws/whats-new]