Shared processing

Virtual processors in the same class have identical code and share access to both data and processing queues in memory. Any virtual processor in a class can run any thread that belongs to that class.

Generally, the database server tries to keep a thread running on the same virtual processor because moving it to a different virtual processor can require some data from the memory of the processor to be transferred on the bus. When a thread is waiting to run, however, the database server can migrate the thread to another virtual processor because the benefit of balancing the processing load outweighs the amount of overhead incurred in transferring the data.

Shared processing within a class of virtual processors occurs automatically and is transparent to the database user.