Ah, of course, thank you! From: tanel@xxxxxxxxxx [mailto:tanel@xxxxxxxxxx] On Behalf Of Tanel Poder Sent: Friday, June 07, 2013 11:10 AM To: Tanel Poder Cc: Walker, Jed S; oracle-l@xxxxxxxxxxxxx Subject: Re: v$sql.disk_reads versus v$sql.physical_read_requests the same goes for the "physical read IO requests" and "physical reads" statistics in v$sesstat/v$sysstat.... -- Tanel Poder Enkitec (The Exadata Experts) Training<http://blog.tanelpoder.com/seminar/> | Troubleshooting<http://blog.tanelpoder.com/> | Exadata<http://www.amazon.com/Expert-Oracle-Exadata-Apress/dp/1430233923> | Voicee App<http://voic.ee/> On Fri, Jun 7, 2013 at 8:08 PM, Tanel Poder <tanel@xxxxxxxxxxxxxx<mailto:tanel@xxxxxxxxxxxxxx>> wrote: disk_reads is number of blocks read physical_read_requests is the number of IO requests done so if all you do is single block reads, the disk_reads = physical_read_requests but if you also do multiblock reads, then the dist_reads should be bigger -- Tanel Poder Enkitec (The Exadata Experts) Training<http://blog.tanelpoder.com/seminar/> | Troubleshooting<http://blog.tanelpoder.com/> | Exadata<http://www.amazon.com/Expert-Oracle-Exadata-Apress/dp/1430233923> | Voicee App<http://voic.ee/> On Fri, Jun 7, 2013 at 8:03 PM, Walker, Jed S <Jed_Walker@xxxxxxxxxxxxxxxxx<mailto:Jed_Walker@xxxxxxxxxxxxxxxxx>> wrote: I was looking over v$sql and noticed it has disk_reads and physical_read_requests. I couldn't tell from the docs exactly what the difference is. I'm guessing disk_reads is the number of disk reads requested, and physical_read_requests is how many reads were actually required from the disk (maybe because of diffs in db block size and disk block size?) Curious if anyone knows for certain? thanks -- //www.freelists.org/webpage/oracle-l -- //www.freelists.org/webpage/oracle-l