SQL*Plus 12.2 ignores %SQLPATH%\LOGIN.SQL
Enabling OS authentication for Oracle databases running on Windows prevents password authenticated connections from other domains without trust relationships. Eg, RMAN running in the pre-production domain wouldn't be able to use a database account password to connect to an RMAN catalogue database in the production domain.
The Oracle database may be prevented from removing datafiles when a tablespace is dropped (including contents and datafiles) on Windows, even with Oracle 12.1.
12c can (and should) use managed service accounts for the Oracle Home User, but there isn't a lot of support information available. Here is my small contribution.
The performance consequences of sorting the result set from SQL using TO_CLOB are not easily found on the internet, so this is a brief note that might help make sense of AWR or ASH reports if the symptoms match.
The oerr utility is useful to find information about Oracle database errors quickly. After decades of neglect, it is finally available on Windows. Sort of.
How to monitor Oracle databases with SCOM, and why OEM is not always the best solution.