ob_bnl_join_cache_size

Description

ob_bnl_join_cache_size specifies the amount of data that is cached during each Batch Nested Loop Join (BNLJ) operation.

Privilege requirements

• Query variables

  • Global level

    The sys tenant 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 values of global system variables.

  • Session level

    The sys tenant and all user tenants can execute the SHOW VARIABLES statement or query the SYS.TENANT_VIRTUAL_SESSION_VARIABLE view (Oracle mode) or the information_schema.SESSION_VARIABLES view (MySQL mode) to obtain the values of session variables.

• Modify variables

  • Global level

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

    • In MySQL mode, MySQL user tenants can modify the values of global system variables if they have the SUPER or ALTER SYSTEM privilege.

    • In Oracle mode, Oracle user tenants can modify the values of global system variables if they have the ALTER SYSTEM privilege.

  • Session level

    The sys tenant and all user tenants can directly modify the values of session variables.

Attributes

Examples

Configure the amount of data that is cached during each Batch Nested Loop Join (BNLJ) operation to 10485760.

• Global level

  obclient> SET GLOBAL ob_bnl_join_cache_size=10485760;
  

• Session level

  obclient> SET ob_bnl_join_cache_size=10485760;