problem consistently getting explain plan with 10046 trace

We have found that we do not always get the 10046 explain plan that gives us the LIO and PIO for each row source with a level 12 report.

This is what we are doing.

alter session set time_statistics=true
alter session set events '10046 trace name context forever, level 12'; <run stuff>
alter session set events '10046 trace name context off';

We find that we get the plan more often if we do a level 8 and if we exit the session the session before running tkprof.

tkprof *.trc *.rep sys=no explain=<username/password>

I don't really want the 'explain plan' you get in sqlplus. I need the one specific to the trace file that gives LIOs and PIOs by row source.

anyone else having this problem?

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