V$PX_PROCESS_SYSSTAT

This view contains information about the sessions running parallel execution.

Column	Datatype	Description
STATISTIC	VARCHAR2(30)	The name of the statistic:
		Servers In Use - the number of PX servers currently performing parallel operations Servers Available - the number of PX servers available to perform parallel operations Servers Started - the number of times the system has had to create a PX server process Server Shutdown - The number of times a PX server process has been shutdown. A PX server process will be shutdown if it has not been used recently. The length of time it may remain "Available" is controlled by the initialization parameter PARALLEL_SERVER_IDLE_TIME. If this value is large, consider increasing the parameter. This will improve performance by avoiding the latency of PX server process creation.
		Servers HWM - the maximum number of concurrent PX server processes If this number is equal to the initialization parameter PARALLEL_MAX_SERVERS, consider increasing the parameter. This could allow you to increase your throughput, especially if your system is under-utilized and the V$SYSSTAT statistic "Parallel operations downgraded to serial" is large. Servers Cleaned Up - The number of times PMON had to clean up a PX server. This should only happen during abnormal termination of a parallel operation. If this number is large, you should determine the cause.
		Sessions - the total number of sessions created by all PX servers Memory Chunks Allocs - the number of large memory chunks allocated by PX servers Memory Chunks Freed - the number of large memory chunks freed Memory Chunks Current - the number of large memory chunks currently being used Memory Chunks HWM - the maximum number of concurrently allocated chunks
		Buffers allocated - the number of times a message buffer has been allocated Buffers freed - the number of times a message buffer has been freed Buffers Current - the number of message buffers currently being used Buffers HWM - the maximum number of concurrently allocated message buffers
VALUE	NUMBER	The value of the statistic