This is a question that I played with for a long time. There have been statements on logical IO performance (“Logical IO is x times faster than Physical IO”), but nobody could answer the question what the actual logical IO time is. Of course you can see part of it in the system and session statistics (v$sysstat/v$sesstat), statistic name “session logical reads”. However, if you divide the number of logical reads by the total time a query took, the logical IO time is too high, because then it assumed all the time the query took was spend on doing logical IO, which obviously is not the case, because there is time spend on parsing, maybe physical IO, etc. Also, when doing that, you calculate an average. Averages are known to hide actual behaviour.