ob_plan_cache_evict_low_percentage

Description

ob_plan_cache_evict_low_percentage specifies the percentage of the memory size at which the plan cache stops evicting plans relative to the absolute value of the memory upper limit.

Privilege requirements

• Query variables

  sys tenants 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 obtain the value of global system variables.

• Modify variables

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

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

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

Attributes

Usage notes

The memory size at which the plan cache stops evicting plans (the low watermark of plan eviction) is calculated as the absolute value of the memory upper limit multiplied by ob_plan_cache_evict_low_percentage divided by 100. For more information about the absolute value of the memory upper limit, see ob_plan_cache_percentage.

Examples

Set the percentage of the memory size at which the plan cache stops evicting plans relative to the absolute value of the memory upper limit to 50.

obclient> SET GLOBAL ob_plan_cache_evict_low_percentage =50;