Where do these large trace files come from in Oracle 12c?

Just had an observation about very large trace files on one of my customers I’m working with at the moment. When I write “very” I mean “VERY” as some grew over 10GB within a few hours. The files contained a ton of such messages: —– Cursor Obsoletion Dump sql_id=5p8a9d4017bq3 —– Parent cursor obsoleted 1 time(s). maxchild=1024 basephd=00007FFB8AD45CB0 phd=00007FFB8AD45CB0 After doing a bit of research I came across this document and an explanation: MOS Note:1955319.1; Huge Trace Files Created Containing “—– Cursor Obsoletion Dump sql_id=%s —–“ Well, we introduced an Enhancement – via an unpublished bug (and I’d guess it is…