You need to know even experts/Guru dose not have complete understanding for this list, maybe they have knowledge about it but not that much, But the most important things in securing database ( new one ) or securing application is early understanding security model very early in the development process and how to develop it. you can read the this book “Oracle security: Step-by-step” by Pete Finnigan he mentioned lot of basic steps to secure oracle database.
From a high level perspective, security is always about risk. If you think that your system is impenetrable, think again. Someone else will always be building a better mousetrap.
For example if we asked ourself as DBA About SQL injection one of the TOP ten Threats in Database
it happens because somebody is writing a Web application that accesses your database which mean if this code writes incorrectly, what happened if the hacker get access to your database thru this code.because of this DBA needs to understand who is access to database and make sure the developers are accessing in a secure way.
Internal/External hacker going to search for Holes in your application to get in,as we know there’s one of attack type used called Buffer Overflow because of this you need to keep you system is up to date patched like usual people most of them not doing that since they worried about if that patch will broke their system or application.
Today a lot of people are ignoring the security side of the job. Many companies don’t have the resources. Until you get hacked, and until you lose data, then you think you can get by with minimal security.
I mention before the in my article about Basic steps to secure Oracle Database some of this article provided with examples i will advise today to bookmark this to keep updated with Oracle Security patches lot of tips to talk about and need to share it here as soon as i can.