On SQL Server, the following query will list all SQL elements that have system-generated names (e.g. indexes, constraints):
select tab.name "table", obj.type "type", obj.name "name"
from (
select null "type", null "name", null "tableId" where 1=0
union select 'index', name, id from sysindexes where name not like '_WA_SYS%'
union select 'primary key', name, parent_obj from sysobjects where xtype='PK'
union select 'foreign key', name, parent_obj from sysobjects where xtype='F'
union select 'check constraint', name, parent_obj from sysobjects where xtype='C'
union select 'unique constraint', name, parent_obj from sysobjects where xtype='UQ'
union select 'default constraint', name, parent_obj from sysobjects where xtype='D'
) obj
inner join sysobjects tab on (tab.id=obj.tableId)
where objectproperty(obj.tableId, 'isMsShipped')=0
and obj.name like '%\_\_%' escape '\'
order by tab.name, obj.type, obj.name
