Вот запрос, который даст вам по таблице общий размер, количество строк и байтов в строке:
select
o.name,
max(s.row_count) AS 'Rows',
sum(s.reserved_page_count) * 8.0 / (1024 * 1024) as 'GB',
(8 * 1024 * sum(s.reserved_page_count)) / (max(s.row_count)) as 'Bytes/Row'
from sys.dm_db_partition_stats s, sys.objects o
where o.object_id = s.object_id
group by o.name
having max(s.row_count) > 0
order by GB desc
А вот запрос, аналогичный приведенному выше, но разбитый по индексу:
select
o.Name,
i.Name,
max(s.row_count) AS 'Rows',
sum(s.reserved_page_count) * 8.0 / (1024 * 1024) as 'GB',
(8 * 1024* sum(s.reserved_page_count)) / max(s.row_count) as 'Bytes/Row'
from
sys.dm_db_partition_stats s,
sys.indexes i,
sys.objects o
where
s.object_id = i.object_id
and s.index_id = i.index_id
and s.index_id >0
and i.object_id = o.object_id
group by i.Name, o.Name
having SUM(s.row_count) > 0
order by GB desc