7 years back when I was in New Delhi, India, I had read Cary Milsap's book Optimizing Oracle Performance from cover to cover. It had enlightened me about Oracle performance.
Here are some of the things we learnt today apart from the regular curriculum:
1. For each row returned you should touch 10 or fewer blocks
2. No. of Logical IOs = No. of tables in a query x No. of rows x 10
3. Nested loops work great with small data sets.
One of the students asked Ric "How do we find out what a query is doing if it is taking a dirt nap" and Rick said that he had never heard of the term "dirt nap". I also never heard it.
Apparently "dirt nap" is a colloquial term which means dead. A dirt nap is when you die, you take the big dirt bath to be buried underground. similar to death.