There's an excellent discussion in http://www.amazon.com/exec/obidos/AS...roduct-details

I don't recommend http://www.amazon.com/exec/obidos/tg...glance&s=books if you want to understand the statspack reports.

http://otn.oracle.com/deploy/perform.../statspack.pdf
http://otn.oracle.com/deploy/perform...G_dialeris.pdf
http://otn.oracle.com/deploy/perform...ng_otn_new.pdf