PARALLEL_ADAPTIVE_MULTI

PARALLEL_ADAPTIVE_MULTI_USER

Property	Description
Parameter type	Boolean
Default value	`true`
Modifiable	`ALTER SYSTEM`
Range of values	`true \| false`

PARALLEL_ADAPTIVE_MULTI_USER, when set to true, enables an adaptive algorithm designed to improve performance in multiuser environments that use parallel execution. The algorithm automatically reduces the requested degree of parallelism based on the system load at query startup time. The effective degree of parallelism is based on the default degree of parallelism, or the degree from the table or hints, divided by a reduction factor.

The algorithm assumes the following:

The system has been tuned for optimal performance in a single-user environment
The parameter PARALLEL_AUTOMATIC_TUNING is set to TRUE

Tables and hints use the default degree of parallelism.

See Also:

Oracle Database Performance Tuning Guide for more information on tuning parallel execution and on the algorithm described here