cputime & elapsedtime where to see first when there is huge difference

1.What are the main places to look when
there is a huge difference between
elapsed_time and cpu_time of v$sql. (elapsed_time>cpu_time).

2. Some cases we found cpu_time is greater than elapsed_time..What could be the reason for this.(elapsed_time

1. Disk I/O usually makes the difference.

2. Multi-CPUs: 4 CPUS can give you 4 seconds CPU per second elapsed.

Quote:

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Originally posted by DaPi
1. Disk I/O usually makes the difference.

2. Multi-CPUs: 4 CPUS can give you 4 seconds CPU per second elapsed.

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Part 2 is exact .. 4 cpus are there.

But point 1 ..I am still searching the exact reasons.
..

Wait time due to I/O that is not part of CPU.

The query is not much i/o intensive..

wat about LIO?

alter session set events '10046 trace name context forever, level 12'


and check the tkprof output of the tracefile. You will see the events for which the session is/was waiting.