Yes.. maybe I didn't ask the right question. The reason this came up was because the DBAs had a report generated showing this SQL as the #1 in the database over the past week. But it's only #1 in terms of elapsed time. When I look at these things, I usually look for actual work: gets, physical reads/writes, cpu time, etc and ignore elapsed time. The rationale being: if it is not doing a physical read/write and it is not using CPU, who cares? So I am wondering if there is something else about "elapsed time" that makes it a good metric for identifying tuning targets. Thanks, Matt From: Mark W. Farnham [mailto:mwf@xxxxxxxx] Sent: Tuesday, February 18, 2014 12:31 PM To: McPeak, Matt; 'ORACLE-L' Subject: RE: I/O waits hurting anyone? That depends largely on two factors: 1) How much of your i/o "wait" is actually cpu/data movement, burning cpu. 2) Whether your i/o is obstructing some other job's need for data access mwf From: oracle-l-bounce@xxxxxxxxxxxxx<mailto:oracle-l-bounce@xxxxxxxxxxxxx> [mailto:oracle-l-bounce@xxxxxxxxxxxxx] On Behalf Of McPeak, Matt Sent: Tuesday, February 18, 2014 12:24 PM To: ORACLE-L Subject: I/O waits hurting anyone? I have a process that executes a lot. Over 6 days it's executed 1.3 million times. The elapsed time per call averages 0.8 seconds, and the I/O wait time per call averages 0.7 seconds. In other words, it spends most of its time waiting. I'll look into all that... my question is more general: am I right in saying that the I/O waits don't load the system in any way and don't hurt any processes besides the one that is waiting? Thanks in advance! Matt