On 29/12/2013 6:01 AM, Amihay Gonen wrote:
Are you taking into account the fact that V$ views look at real memory in real time and do not follow the Consistent Read model?Where I can see the numbers are near but not summed up .For example db time [0]= 3,991,739 <> 3,987,789+13,352+13,352+9,402 = 4,023,895
In other words, it is quite possible for some small variations to occur simply because the V$ views (X$ tables, and the associated code) query each memory location in real time, while the system is actually performing operations.
My experience is that the 'drift' in the V$/X$ information is exacerbated in certain environments, such as virtualization. (You do not mention your environment in detail.) I tend to be surprised when the numbers actually 'add up exactly'.
/Hans