Below is the result of my statspack, please give me some opinion of what you think:

Instance Efficiency Percentages (Target 100%)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Buffer Nowait %: 100.00 Redo NoWait %: 100.00
Buffer Hit %: 71.19 In-memory Sort %: 100.00
Library Hit %: 91.89 Soft Parse %: 74.60
Execute to Parse %: 88.33 Latch Hit %: 100.00
Parse CPU to Parse Elapsd %: 66.67 % Non-Parse CPU: 92.16



Top 5 Timed Events
~~~~~~~~~~~~~~~~~~ % Total
Event Waits Time (s) Ela Time
-------------------------------------------- ------------ ----------- --------
control file parallel write 357 1 34.90
CPU time 1 28.03
db file scattered read 121 0 16.65
control file sequential read 302 0 14.45
db file sequential read 59 0 5.78



The buffer hit ratio is low, what parameter can I increase??? what about the CPU time on top 5 events????

thanks