V$PX_PROCESS

9.148 V$PX_PROCESS_SYSSTAT

V$PX_PROCESS_SYSSTAT contains information about the sessions running parallel execution.

Column Datatype Description

Column	Datatype	Description
`STATISTIC`	`VARCHAR2(30)`	Name of the statistic: `Buffers` `Allocated` - Number of times a message buffer has been allocated `Buffers` `Current` - Number of message buffers currently being used `Buffers` `Freed` - Number of times a message buffer has been freed `Buffers` `HWM` - Maximum number of concurrently allocated message buffers `Chunk` `Lists` - Number of memory chunk lists `Memory` `Chunks` `Allocated` - Number of large memory chunks allocated by PX servers `Memory` `Chunks` `Current` - Number of large memory chunks currently being used `Memory` `Chunks` `Freed` - Number of large memory chunks freed `Memory` `Chunks` `HWM` - Maximum number of concurrently allocated chunks `Memory` `Chunks` `Permanent` - Number of large memory chunks allocated permanently `Server` `Sessions` - Total number of sessions created by all PX servers `Servers` `Available` - Number of PX servers available to perform parallel operations `Servers` `Cleaned` `Up` - Number of times PMON had to clean up a PX server. This should only happen during nonstandard termination of a parallel operation. If this number is large, then you should determine the cause. `Servers` `Highwater` - Maximum number of concurrent PX server processes If this number is equal to the `PARALLEL_MAX_SERVERS` initialization parameter, then 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` `In` `Use` - Number of PX servers currently performing parallel operations `Servers` `Shutdown` - Number of times a PX server process has been shut down. A PX server process will be shut down if it has not been used recently. If this value is large, then consider increasing the parameter. This will improve performance by avoiding the latency of PX server process creation. `Servers` `Started` - Number of times the system has had to create a PX server process
`VALUE`	`NUMBER`	Value of the statistic
`CON_ID`	`NUMBER`	The ID of the container to which the data pertains. Possible values include: `0`: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs. `1`: This value is used for rows containing data that pertain to only the root n: Where n is the applicable container ID for the rows containing data

STATISTIC

VARCHAR2(30)

Name of the statistic:

Buffers Allocated - Number of times a message buffer has been allocated
Buffers Current - Number of message buffers currently being used
Buffers Freed - Number of times a message buffer has been freed
Buffers HWM - Maximum number of concurrently allocated message buffers
Chunk Lists - Number of memory chunk lists
Memory Chunks Allocated - Number of large memory chunks allocated by PX servers
Memory Chunks Current - Number of large memory chunks currently being used
Memory Chunks Freed - Number of large memory chunks freed
Memory Chunks HWM - Maximum number of concurrently allocated chunks
Memory Chunks Permanent - Number of large memory chunks allocated permanently
Server Sessions - Total number of sessions created by all PX servers
Servers Available - Number of PX servers available to perform parallel operations
Servers Cleaned Up - Number of times PMON had to clean up a PX server. This should only happen during nonstandard termination of a parallel operation.

If this number is large, then you should determine the cause.
Servers Highwater - Maximum number of concurrent PX server processes

If this number is equal to the PARALLEL_MAX_SERVERS initialization parameter, then 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 In Use - Number of PX servers currently performing parallel operations
Servers Shutdown - Number of times a PX server process has been shut down. A PX server process will be shut down if it has not been used recently.

If this value is large, then consider increasing the parameter. This will improve performance by avoiding the latency of PX server process creation.
Servers Started - Number of times the system has had to create a PX server process

VALUE

NUMBER

Value of the statistic

CON_ID

NUMBER

The ID of the container to which the data pertains. Possible values include:

0: This value is used for rows containing data that pertain to the entire CDB. This value is also used for rows in non-CDBs.
1: This value is used for rows containing data that pertain to only the root
n: Where n is the applicable container ID for the rows containing data