Long shot, but...
I have a 13.0 instance running on SQLServer (standard edition, not enterprise - I realise this is "not supported").
Periodically the database maxes out, 100% CPU for a while, then all is OK again for a while.
We've had a look at the database activity, and there seems to be a few suspect statements; beginning with "with OBS_HIERARCHIES (unit_id, obs_name, obs_path, type_id)".
I've traced that code in the Clarity software, and it is in the "...\META-INF\nmc\pmd\obsPMD.xml" and seems to be connected with the OBS auto-suggest functionality (statements "nmc.obsSuggestions", "nmc.obsSuggestionsForObsType" and "nmc.obsSuggestionsForDepartments").
I'm very confused since this functionality is connected to user-data entry, but the errant SQL appears to be running at the same time on a mirror system that had no logged-in users. There are no scheduled-jobs (that I can see) running around this time either.
Any clues/inspired-insight then?