The latch free wait event has three parameters: latch address, latch number, and the number of tries. In Oracle Database 10g, depending on the latch wait event, it can fall under the Concurrency, Configuration, or Other wait class. Keep the following key thoughts in mind when dealing with the latch free wait event.
Latches apply only to memory structures in the SGA. They do not apply to database objects. An Oracle SGA has many latches, and they exist to protect various memory structures from potential corruption by concurrent access.
The Oracle session is waiting to acquire a specific latch. The appropriate action to take depends on ...