| Property | Description |
|---|---|
| Parameter type | Integer |
| Default value | 0 |
| Modifiable | ALTER SESSION |
| Range of values | 0 to 100 |
| Real Application Clusters | Multiple instances can have different values. |
PARALLEL_MIN_PERCENT operates in conjunction with PARALLEL_MAX_SERVERS and PARALLEL_MIN_SERVERS. It lets you specify the minimum percentage of parallel execution processes (of the value of PARALLEL_MAX_SERVERS) required for parallel execution. Setting this parameter ensures that parallel operations will not execute sequentially unless adequate resources are available. The default value of 0 means that no minimum percentage of processes has been set.
Consider the following settings:
PARALLEL_MIN_PERCENT = 50 PARALLEL_MIN_SERVERS = 5 PARALLEL_MAX_SERVERS = 10
If 8 of the 10 parallel execution processes are busy, only 2 processes are available. If you then request a query with a degree of parallelism of 8, the minimum 50% will not be met.
You can use this parameter in conjunction with PARALLEL_ADAPTIVE_MULTI_USER. In a multi-user environment, an individual user or application can set PARALLEL_MIN_PERCENT to a minimum value until sufficient resources are available on the system and an acceptable degree of parallelism is returned.
See Also:
Oracle Database Performance Tuning Guide for more information on tuning parallel execution
"PARALLEL_MAX_SERVERS", "PARALLEL_MIN_SERVERS", and "PARALLEL_ADAPTIVE_MULTI_USER"