Physical Database Design
For the runtime engine to execute a SQL statement with adequate performance, you must provide it with a properly sized machine that has an adequate SGA and an adequate PGA. However, physical database design is also crucial: even with a reasonably sized machine, a well-written SQL statement, and a CBO that makes all its cardinality estimates perfectly, you are unlikely to get decent performance unless you pay attention to the physical database design.
A WORD ABOUT EXADATA
There are those who suggest that one of the benefits of Exadata is that you don’t have to worry about physical database design: full table ...