I would like understand tuning and tkprof

Hello,

    I have executed tkprof and my explain plan is next :

I would like understand :

I have inserted 24 rows and and I have executed 23 access to the disk.
How can I improve by reduce the access to the disk ? because I have 24 rows and 23 access to the disk.

For me if I have the memory bigger for the disk then I can reduce the number access to the disk.

Who can explain me the process ?

And I see on my result the optimizer mode = ALL_ROWs
is it better or 'FIRST_ROWS is better ?

best regards

Thanks for your help