This parameter defines the group name with system maintenance (SYSMAINT) authority.
SYSMAINT has privileges to perform maintenance operations on all databases associated with an instance without having direct access to data.
Group names on all platforms are accepted as long as they adhere to the length limits specified in SQL and XML limits.
To restore the parameter to its default (NULL) value, use UPDATE DBM CFG USING SYSMAINT_GROUP NULL. You must specify the keyword NULL in uppercase.