Supporting the idea of Tim, I am writing this post to say that my favorite feature of Oracle Database is "Multitenant". Oracle Multitenant Architecture was introduced in Oracle Database 18.104.22.168 (12c). Indeed when I was learning Oracle 12c in 2012 I was impressed with this new architecture and how Oracle Designed it. With this new Architecture several new concepts appeared in 12c, for example "Common Users" and "Local Users"; "Privileges granted commonly" and "Privileges granted locally"; "Container Database", "Pluggable Database" and "Seed". As you can see from Oracle 11g to Oracle 12c there were big and good changes, it was not the same case when we upgraded our knowledge from 10g to 11g where several features were introduced but not a new architecture. Probably I like this architecture more than the other features because since 2012 I was reading about it, I wrote several articles for almost every database feature introduced in 22.214.171.124 and in 126.96.36.199 (just put in google search a feature name followed of my name and you will find an article), I delivered several sessions of Multitenant in several Oracle Events around the world, I was part of Beta Test Program in 2015 for 12cR2 for Multitenant and also I was one of the Technical Reviewers of the Book written by Frank Pachot, Vit Spinka and Anton Els called "Oracle Database 12c Release 2 Multitenant (1st Edition)" with the Editorial "Oracle Press", the other Technical Reviewer was Arup Nanda. So imagine! how I love this new architecture after 4 years of studying / working with it!
There are several benefits of Using Oracle Multitenant:
Oracle Database have more than 500 new features in 188.8.131.52, it has more than 600 new features in 184.108.40.206, Oracle Database 12cR2 is coming soon with hundreds of new features.... What's your favorite one?