I am getting following in ADDM Report:-
Time spent on the CPU by the instance was responsible
 for a substantial part of database time.
Wait class "User I/O" was consuming significant database time.
How could i know the reason behind high CPU Utilizaion and
high User I/O.

Bad SQL is not responsible for high CPU Utilization in this case.
Instead "Logminer" processes and "STREAMS Capture" is responsible
for high cpu utilization.Can you give me any suggesions or 
document so that I could investigate why Logminer process and
STREAMS Capture process is utilizing large amount of CPU.
I have one more question:-
Everytime I am running ADDM Report after taking AWR it is giving me following statement in the end:-
WARNING: The optimal SGA size could not be determined because of incomplete AWR snapshots.
But I want ADDM to determine optimal SGA Size.How can i acheive this