What are the units for time_waited in v$active_session_history?

Question

I need an Oracle reference. Thanks.

Answer 1

Micro-seconds.
Hard to find in docs.
But if you lock a table and sleep in session #1 with something like:
begin
lock table foo in exclusive mode;
exec dbms_lock.sleep(60);
end;
And try an insert into foo in session #2,
you will find that the sum of time_waited for the query
is about equal to the sleep time, if time_waited is treated as micro-seconds.