Esta consulta enumerará el tamaño total que ocupa una tabla:índice agrupado, montón y todos los índices no agrupados:
SELECT
s.Name AS SchemaName,
t.NAME AS TableName,
p.rows AS RowCounts,
SUM(a.total_pages) * 8 AS TotalSpaceKB,
SUM(a.used_pages) * 8 AS UsedSpaceKB,
(SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB
FROM
sys.tables t
INNER JOIN
sys.schemas s ON s.schema_id = t.schema_id
INNER JOIN
sys.indexes i ON t.OBJECT_ID = i.object_id
INNER JOIN
sys.partitions p ON i.object_id = p.OBJECT_ID AND i.index_id = p.index_id
INNER JOIN
sys.allocation_units a ON p.partition_id = a.container_id
WHERE
t.NAME NOT LIKE 'dt%' -- filter out system tables for diagramming
AND t.is_ms_shipped = 0
AND i.OBJECT_ID > 255
GROUP BY
t.Name, s.Name, p.Rows
ORDER BY
s.Name, t.Name
Si desea separar el espacio de tabla del espacio de índice, debe usar AND i.index_id IN (0,1)
para el espacio de tablas (index_id = 0
es el espacio del montón, index_id = 1
es el tamaño del índice agrupado =páginas de datos) y AND i.index_id > 1
para el espacio de solo índice