ANSWER：（这里是重点，点开链接即可查看官方以及非官方的说明）
Official answer is at:
http://docs.oracle.com/cd/E11882_01/license.112/e47877/editions.htm#DBLIC109
Non-official answers:
http://www.dba-oracle.com/art_so_oracle_standard_enterprise_edition.htm
http://www.orafaq.com/faq/what_is_the_difference_between_the_enterprise_standard_and_personal_editions_of_oracle (an old article)
Any specific feature you're considering?
QUESTION：
Thank you for your prompt reply, which is very useful to me.
I got many unavailable features to explain my failures of using AWR and so on.(Oracle 11.2.0.4)
How can I use these features,such as Fast RMAN Compression (ZLIB),SQL Plan management and so on?Just use lincese and change parameter of database?
ANSWER：（这里给出忠告，如果没买企业版，不要使用，不然有可能承担法律责任）
Listen to neverinit. Better safe than sorry.
If your client doesn't want to buy EE, just live with SE. In real experience, lack of AWR, Fast RMAN Compression (ZLIB),SQL Plan management is nothing serious. You can run a job to run Statspack, or gather stats with your own script. You can compress backup pieces with gzip. SE doesn't support SQL Plan Management but supports SQL outlines. (Oracle deprecates outlines in favor of SPM, maybe partially out of this greedy motive?) Just be clever in rolling your own tools and finding workarounds.
The only big problem is actually this fact: Oracle software is designed to have all fancy features readily usable EVEN IF YOU HAVE NOT PURCHASED IT. I say it's a big problem because if you accidentally use it, as shown in DBA_FEATURE_USAGE_STATISTICS, Oracle auditors (if you are audited) will get you! It takes a lot of legal talk to convince Oracle that you did it unintentionally and you may still end up paying the fine. This happened to an American university a few years ago. The correct software design should be such that if you haven't paid for a feature, the feature should not even be enabled for you.
QUESTION：
Thanks for your kind reminding，I will improve my skills of managing Oracle.
Besides, I will keep our client on our guard.Next week there will be an Oracle expert to check and optimize the environment，I wll ask him about the big problem and seek for a better solution.
ANSWER：
Oracle software is designed to have all fancy features readily usable EVEN IF YOU HAVE NOT PURCHASED IT.
To be more specific, Oracle is not doing this right in the sense that if your database is Enterprise Edition, the control_management_pack_access parameter has the default value 'DIAGNOSTIC+TUNING', even if you have not purchased licenses for these two options. I just experimented with
alter system set control_management_pack_access = none;
It indeed takes effect. A query against v$active_session_history no longer returns any row. But to my surprise, I can still run AWR report (@?/rdbms/admin/awrrpt.sql).
On the other hand, Oracle is right in not allowing Enterprise Edition features if your database is Standard Edition by setting that parameter to NONE by default. (I didn't verify but I'll trust the documentation.)
