This post explains how you can check which options or features are used in the database. This is particularly useful for licensing purposes or when you want to de-install a certain option.
This can be achieved through the DBA_FEATURE_USAGE_STATISTICS view. This view will list the feature usage on a per patchset basis. So the combination of feature name and version is unique.
Typically one can verify the features used using the following query:
select * from DBA_FEATURE_USAGE_STATISTICS where detected_usages > 0 order by name, version;
To get a list of options that are not in use:
select * from DBA_FEATURE_USAGE_STATISTICS where detected_usages = 0 order by name, version;
Note: If the DBID has been changed via nid command, the query against the DBFUS view MUST include the current DBID otherwise the results returned will be incorrect.