ob_plan_cache_evict_low_percentage

Description

ob_plan_cache_evict_low_percentage specifies the percentage of the memory size at which plan cache eviction stops, relative to the maximum memory size.

Privilege requirements

• Query variables

  sys and all user tenants can execute the SHOW VARIABLES statement or query the SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE view (Oracle mode) or the information_schema.GLOBAL_VARIABLES view (MySQL mode) to view the value of a global system variable.

• Modify variables

  • sys tenants can directly modify the value of a global system variable.

  • MySQL user tenants must have the SUPER or ALTER SYSTEM privilege to modify the value of a global system variable.

  • Oracle user tenants must have the ALTER SYSTEM privilege to modify the value of a global system variable.

Attributes

Usage notes

The memory size at which plan cache eviction stops (the low watermark of plan cache eviction) is calculated as follows: memory size at which plan cache eviction stops = maximum memory size × ob_plan_cache_evict_low_percentage / 100. For more information about the maximum memory size, see ob_plan_cache_percentage.

Examples

Set the percentage of the memory size at which plan cache eviction stops, relative to the maximum memory size, to 50.

obclient> SET GLOBAL ob_plan_cache_evict_low_percentage =50;