Thanks guys. I will run trace, even if it does take an act of congress and a letter from my doctor to get the dbas to give my the necessary privs. I'll let you know how it went. Thanks again, Mike On Mon, Feb 7, 2011 at 9:59 AM, Daniel W. Fink <daniel.fink@xxxxxxxxxxxxxx>wrote: > Without additional information, the only option available is "Guess". > > Run extended sql trace (dbms_monitor.session_trace_enable, event 10046, > etc), run the trace file(s) through tkprof and analyze the differences. > > > > On 2/7/2011 10:49 AM, Michael Moore wrote: > > I've been trying to tune a SQL statement but I get very inconsistent > results. > > I always start with: > alter system flush shared_pool; > alter system flush buffer_cache; > > Then I run the SQL, but the first time I run it, it can take as much as 7 > minutes. On the 2nd, 3rd, and 4th runs, it takes > 40 sec, 49 sec, 35 sec respectively. > > So my question is: What might account for the huge difference in run time > between the first run and successive runs? > > Thanks, > Mike > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 9.0.872 / Virus Database: 271.1.1/3428 - Release Date: 02/07/11 > 00:34:00 > > >