Djordje,

1. You're right; in Oracle8, tim is measured in centiseconds (0.01s).

2. The value is the same as that found in v$timer.hsecs.

3. We're not sure whether the Epoch for this clock is even meaningful or
not (I don't think we've been able to prove that the value resets when
you do an instance restart. Perhaps the value is a modulus of a
gettimeofday() value.)

4. Item #3 has never really bothered us, because all we generally care
about is *relative* tim values, not absolute ones. You can establish a
mapping of tim values to wall clock values by comparing the timestamp in
a '***' line to the nearest tim value to it.

5. Oracle9i makes life a little more fun, because tim values become
microsecond (0.000001s) values, and they appear to be unadulterated
gettimeofday() values, with an Epoch of 00:00:00 UTC, 1 January 1970 (we
*think* this is true on all platforms). Hence, it becomes easy to
convert from tim values to wall clock values and back with a simple Perl
script that uses str2time and time2str function calls.

6. Finally, a minor detail correction: the tim of a given line in the
trace file tells you the time at which the given cursor action
*completed*. You certainly aren't incorrect by saying it's the time that
something "ran," but saying "completed" is a little more precise.


Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com

Upcoming events:
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-----Original Message-----
Jankovic
Sent: Friday, January 24, 2003 6:55 AM
To: Multiple recipients of list ORACLE-L

Anybody knows what is the reference point for the timing used in the
"tim"
column in the trace output, like in:

PARSE #3:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=832261739
EXEC #3:c=0,e=0,p=0,cr=0,cu=0,mis=0,r=0,dep=0,og=4,tim=832261739

Apparently the scale is 100 per second for 8i and 976,562.5
(1,000,000,000/1024) for 9, but I am not quite clear what could be the
reference time (the time when counting of tim starts).  In different
databases I tried it, it is usually few months to a year back.

BTW, this column can be used if one needs to find out the exact time
when a
query from the trace was run.

Thanks.

Djordje

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