Hello Gurus, Experts and Pundits...
We have a most annoying problem right now. There is a piece of code that has always run in good time on our database that is now hanging.
To cut a very long story short, we have found some kind of workaround in that restarting the database seems to allow the code to run. Once it has run, the next time we issue that statement it hangs again.
We are nonplussed. Nothing runs on this database excepts this code, and we cant find any changes that have been made to make this an issue.
Would any one know why simply "turning it on and off again" seems to resolve the issue this one time? I understand that things get cached in memory and that a reboot flushes these.
We did find that the OEM auto tuning task applied a lot of tuning profiles to the code, and we have disabled that thinking that somehow the new explain plan had hobbled the query.
Does anyone know if there are any other "auto" tasks in 12C that might be tampering with this code?
This is an urgent issue and my hair is starting to fall out with all the head scratching!
Red Hat Enterprise Linux Server release 7.2
12.1.0.2.0