PARALLEL_THREADS_PER_CPU

Property	Description
Parameter type	Integer
Default value	Operating system-dependent, usually 2
Modifiable	ALTER SYSTEM
Range of values	Any nonzero number

Note:

This parameter applies to parallel execution in exclusive mode as well as in a Real Application Clusters environment.

PARALLEL_THREADS_PER_CPU specifies the default degree of parallelism for the instance and determines the parallel adaptive and load balancing algorithms. The parameter describes the number of parallel execution processes or threads that a CPU can handle during parallel execution.

The default is platform-dependent and is adequate in most cases. You should decrease the value of this parameter if the machine appears to be overloaded when a representative parallel query is executed. You should increase the value if the system is I/O bound.

Note:

1. Query for the current value of the parameter

select name, value, isdefault, isses_modifiable, issys_modifiable,

isinstance_modifiable, isdeprecated, description

from v$parameter where upper(name) = ‘PARALLEL_THREADS_PER_CPU’;

NAME	VALUE	IS DEFAULT	ISSES_ MODIFIABLE	ISSYS_ MODIFIABLE		ISINSTANCE_ MODIFIABLE	IS DEPRECATED	DESCRIPTION
parallel_threads_per_cpu	2	TRUE	FALSE	IMMEDIATE	TRUE		FALSE	number of parallel execution threads per CPU

Oracle initializatoin parameters