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.
Attention: This parameter must be NULL for Windows clients when system security is used (that is, authentication is CLIENT, SERVER, or any other valid authentication). This is because the Windows operating systems do not store group information, thereby providing no way of determining if a user is a member of a designated SYSMAINT group. When a group name is specified, no user can be a member of it.
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.