ob_plan_cache_evict_high_percentage

Description

ob_plan_cache_evict_high_percentage specifies the percentage of the memory size that triggers the eviction of plan cache entries relative to the absolute value of the maximum memory size for the plan cache.

Privilege requirements

• Query variables

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

• Modify variables

  • In the sys tenant, you can directly modify the values of global system variables.

  • In a MySQL user tenant, you must have the SUPER or ALTER SYSTEM privilege to modify the values of global system variables.

  • In an Oracle user tenant, you must have the ALTER SYSTEM privilege to modify the values of global system variables.

Attributes

Usage notes

The memory size that triggers the eviction of plan cache entries (high watermark) = absolute value of the maximum memory size for the plan cache × ob_plan_cache_evict_high_percentage/100. For more information about the absolute value of the maximum memory size for the plan cache, see ob_plan_cache_percentage.

Examples

Set the percentage of the memory size that triggers the eviction of plan cache entries relative to the absolute value of the maximum memory size for the plan cache to 90.

obclient> SET GLOBAL ob_plan_cache_evict_high_percentage =90;