How To Check Which Oracle Features are Enabled ?

There is a very good view DBA_FEATURE_USAGE_STATISTICS . Its function is to display information about database feature usage statistics. Oracle 10g will keep track of any of its features that are being used.   As an example, if we SELECT from any of the Oracle Diagnostic Pack and Tuning Pack views like V$ACTIVE_SESSION_HISTORY, the database will record our usage of it in this DBA view.  

Some of the information tracked are :

•  Name of the feature
•  Number of times the system has detected usage for the feature
•  First sample time the system detected usage of the feature
•  Last sample time the system detected usage of the feat

The below sql will give the detail of the oracle services which are being used.

SQL> select NAME, VERSION, DETECTED_USAGES, CURRENTLY_USED, FIRST_USAGE_DATE, LAST_USAGE_DATE from DBA_FEATURE_USAGE_STATISTICS where CURRENTLY_USED  = 'TRUE' order by 1,2;

Output : 

How to  check the Oracle Edition  : 
We can the check the oracle edition i.e; whether it is enterprise edition or standard edition by using the below command :

SQL>select * from product_component_version;

PRODUCT                                                     VERSION                 STATUS

----------------------------------                        -------------               ------------
NLSRTL                                                         11.2.0.1.0             Production
Oracle Database 11g Enterprise Edition      11.2.0.1.0             Production
PL/SQL                                                         11.2.0.1.0             Production
TNS for 32-bit Windows:                              11.2.0.1.0             Production


Enjoy    :-)