Why my indexes monitoring status change to 'no'? On one of my production Oracle database 11g Standard Edition I have a lot (a very lot of) indexes. Some of them (majority) are created by the application installer, others are created by me when I identify a request who need some dba work.
I'm pretty sure that some of them aren't used at all and I want to identify them.

For that task, I alter all my table &amp; index setting MONITORING status.

After a while (several weeks) I watched about used status :

SELECT index_name, table_name, monitoring, used,
       start_monitoring, end_monitoring
  FROM v$object_usage
 ORDER BY index_name;




I notice that a lot of indexes have now a NOMONITORING status ...

I search to understand what happened and why about this status.

Except the regular ALTER INDEX index_name NOMONITORING USAGE query, what is likely to change this? Does anyone know a process (a standard Oracle's in-dictionary process) that remove the MONITORING status?
One possible reason:

Bug 16311211 : REBUILDING INDEX ALTER SETTING THE MONITORING TO OFF

The bug is said to be fixed on version 12.2 and there are one-off patches for 11.2.0.3 and 11.2.0.4 as well.