Others have answered most of this; I'll add a summary... 1. You can tell whether timed_statistics was activated by checking your raw trace data. If you see any non-zero value for a tim field, it was on. 2. The Oracle kernel gets its CPU time statistics from calls to the getrusage system call (times on HP-UX). The getrusage function gets the information from the OS process table. Except on Solaris with microstate accounting activated, the OS process table gets its CPU statistics by sampling at 0.01-second intervals. Of course, data sampled at 0.01-second intervals are accurate only to +/-0.01 seconds per sample. For events that execute on the order of microseconds, odds are that there will be significant error. But summing these values over a large sample (like in a big trace file) still makes sense. Full details (pictures, etc.) about all this are in the book "Optimizing Oracle Performance." Cary Millsap Hotsos Enterprises, Ltd. http://www.hotsos.com * Nullius in verba * Upcoming events: - Performance Diagnosis 101: 3/23 Park City, 4/6 Seattle - Hotsos Symposium 2004: March 7-10 Dallas - Visit www.hotsos.com for schedule details... -----Original Message----- From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of ryan.gaffuri@xxxxxxx Sent: Monday, March 08, 2004 1:50 PM To: oracle-l@xxxxxxxxxxxxx Subject: tkprof and parse count? Below is a simple tkprof output. Why is my parse count = 4? if there is no CPU time used? I take this to mean, I did not incur a hard parse? How come the 'count' goes up? I can't find this in the docs on metalink. select 2 from dual call count cpu elapsed disk query current rows ------- ------ -------- ---------- ---------- ---------- ---------- ---------- Parse 4 0.00 0.00 0 0 0 0 Execute 4 0.00 0.00 0 0 0 0 Fetch 8 0.00 0.00 0 12 0 4 ------- ------ -------- ---------- ---------- ---------- ---------- ---------- total 16 0.00 0.00 0 12 0 4 ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html ----------------------------------------------------------------- ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request@xxxxxxxxxxxxx put 'unsubscribe' in the subject line. -- Archives are at //www.freelists.org/archives/oracle-l/ FAQ is at //www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------