Start/stop trace between removing trace files

Question

Hi,
I have the following problem.
I put some Oracle session on trace (I use sys.dbms_support.start_trace_in_session). Then I make some test. I close the trace (I use sys.dbms_support.stop_trace_in_session). I analyze the trace files (tkprof) and I make some tuning.
Then I'd like to remove the trace files (*.trc) and start the trace again for checking if the tuning was efficient.
It seems not possible. Event if I start the trace again I can't see and trc files.
In order to solve the problem I must to bounce the application I want to trace (so that the Oracle sessions start again).
Any hint?
Thanks, Max

Answer 1

In that case, you will need to parse the trace file to identify the start and stop of the trace. Below is an example from a 10gR2 trace. Notice the line starting with the *** that contains the date. It comes between the stop of the trace and the start of another trace. You cannot use this line alone to signify the start of a trace as similar lines are emitted in the trace file when there are long delays between writes to the file.
=====================
PARSING IN CURSOR #2 len=55 dep=0 uid=0 oct=42 lid=0 tim=330900979 hv=2217940283 ad='2fdd5ef8'
alter session set events '10046 trace name context off'
END OF STMT
PARSE #2:c=0,e=52,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,tim=330900976
BINDS #2:
EXEC #2:c=0,e=85,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,tim=330901247
*** 2007-02-20 11:55:55.026
=====================
PARSING IN CURSOR #4 len=69 dep=0 uid=0 oct=42 lid=0 tim=386816222 hv=3164292706 ad='2fdd6980'
alter session set events '10046 trace name context forever, level 12'
END OF STMT
EXEC #4:c=0,e=60,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=1,tim=386816218
WAIT #4: nam='SQL*Net message to client' ela= 2 driver id=1111838976 #bytes=1 p3=0 obj#=258 tim=386816593
WAIT #4: nam='SQL*Net message from client' ela= 105 driver id=1111838976 #bytes=1 p3=0 obj#=258 tim=386816748
=====================