Oracle的体系太庞大了，对于初学者来说，难免会有些无从下手的感觉，什么都想学，结果什么都学不好，所以把学习经验共享一下，希望让刚刚入门的人对oracle有一个总体的认识，少走一些弯路。

-Oracle' s system is too large, and for beginners, some can not start feeling, what want to learn, learn the outcome of anything bad, so you put the learning experience to share, to give people just getting started on the oracle has an overall understanding and less take some detours.