In the V$SESSION view, Oracle provides information about the session waits: B) When the WAIT_TIME column has a value of 0, it signifies that the session is currently waiting for a resource. This column represents the duration of the current or last wait. C) If the session is not actively waiting, the WAIT_TIME column shows the time the session spent waiting for the last wait event. If the STATE column is showing "WAITED KNOWN TIME", it means the session is not currently waiting, but it indicates the time for which it had waited. Reference: Oracle Database Reference, 19c Oracle Database Performance Tuning Guide, 19c
