Page History
...
You can use the More... option in the Association controls to populate the association area with a subset of statistics based on class. For example, you can click Statistics>Cache or Statistics>Debug Statistics > Cache or Statistics > Debug. Some statistics are classified more than once. For example, Buffer is Pinned Count is classified as both Cache and SQL.
...
For our example, we will examine how a number of hard parses affects the parse time. If we look at the Hard Parse Ratio graph in the Main area, we can observe that the hard parse ratio increased to around 50% at 6 PM, meaning that some new statements were executed or required reloading. Consequently, the total parse time increased to around 15 minutes. Then the number of statements that required parsing remained fairly constant (shown on the Soft Parse graph), but the hard parses fell away and so did the parse times. This example explains why it is a good idea to use bind variables or cursor sharing.