ob_plan_cache_evict_high_percentage

Description

ob_plan_cache_evict_high_percentage specifies the percentage of the memory size that triggers plan cache eviction relative to the absolute value of the memory upper limit.

Privilege requirements

• Query variables

  sys tenants and all user tenants can use the SHOW VARIABLES statement or the SYS.TENANT_VIRTUAL_GLOBAL_VARIABLE view (Oracle-compatible mode) and the information_schema.GLOBAL_VARIABLES view (MySQL-compatible mode) to view the values of global system variables.

• Modify variables

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

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

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

Attributes

Usage notes

The memory size that triggers plan cache eviction (high watermark) is calculated as the absolute value of the plan cache memory upper limit multiplied by ob_plan_cache_evict_high_percentage divided by 100. For more information about the absolute value of the plan cache memory upper limit, see ob_plan_cache_percentage.

Examples

Set the percentage of the memory size that triggers plan cache eviction relative to the absolute value of the memory upper limit to 90.

obclient> SET GLOBAL ob_plan_cache_evict_high_percentage =90;