Syntax:
DROP RESOURCE GROUP group_name [FORCE]

DROP RESOURCE GROUP is used for resource group management (see
https://dev.mysql.com/doc/refman/8.0/en/resource-groups.html). This
statement drops a resource group. It requires the RESOURCE_GROUP_ADMIN
privilege.

group_name identifies which resource group to drop. If the group does
not exist, an error occurs.

The FORCE modifier determines statement behavior if the resource group
has any threads assigned to it:

o If FORCE is not given and any threads are assigned to the group, an
  error occurs.

o If FORCE is given, existing threads in the group are moved to their
  respective default group (system threads to SYS_default, user threads
  to USR_default).

Examples:

o Drop a group, failing if the group contains any threads:

DROP RESOURCE GROUP rg1;

o Drop a group and move existing threads to the default groups:

DROP RESOURCE GROUP rg2 FORCE;

Resource group management is local to the server on which it occurs.
DROP RESOURCE GROUP statements are not written to the binary log and
are not replicated.

URL: https://dev.mysql.com/doc/refman/8.0/en/drop-resource-group.html

