How to check what the Oracle server is busy with?

Question

Oracle

Hello.
I have an instance of Oracle Database 12c Enterprise Edition Release 12.2.0.1.0 - 64bit Production Picked
up another instance today on a different machine.
After a while, the first copy began to do something while utilizing up to 30% of the CPU.
I went under sys and checked the activities in DBMS jobs and SCHEDULERS_jobs, nothing interesting.
on sessions, except for the developer, nothing, BUT he continues to utilize the CPU.
How else is it possible to diagnose an instance?

Answer 1

Enterprise Manager Database Express