参考SQL2005, 2008和2012的系统存储过程master.sys.sp_spaceused代码后，写了下面一条语句来方便平时统计所有用户表尺寸大小。
可以结合sp_MSforeachdb再遍历所有用户数据库查看所有表的尺寸大小，注意它的参数@sql不能超过nvarchar(2000)，这里就不贴出代码了。
另外还可以定期运行并将结果保存下来，以便观察数据变化趋势。
查询单个数据库的所有用户表尺寸大小：
Select @@servername as ServerName,db_name() as DBName ,object_id as ObjectID, schema_name(schema_id) as SchName, name as TableName
,Rowcnt as Rows,Columns,Indexes,RowLength
,ReservedKb, TableUsedKb
,UsedKb-TableUsedKb as IndexUsedKb,ReservedKb-UsedKb as UnusedKb
,create_date as CreateDate,modify_date as LastModifiedDate, getutcdate() as TrackingUTCTime
From
(select
object_id
,schema_id
,name
,(Select max(row_count) from sys.dm_db_partition_stats p with(nolock) where p.object_id=t.object_id and p.index_id < 2) as Rowcnt
,(Select Count(1) from dbo.syscolumns with(nolock) where id = t.object_id) as Columns
,(Select Count(distinct index_id) from sys.dm_db_partition_stats p with(nolock) where p.object_id=t.object_id) as Indexes
,(SELECT SUM(length) FROM dbo.syscolumns with(nolock) WHERE id = t.object_id) as RowLength
,IsNull((Select SUM(reserved_page_count) from sys.dm_db_partition_stats p with(nolock) where p.object_id=t.object_id),0)*8
+ IsNull((Select sum(reserved_page_count)
FROM sys.dm_db_partition_stats p2 with(nolock)
inner join sys.internal_tables it with(nolock) on p2.object_id = it.object_id
WHERE it.parent_id = t.object_id
AND it.internal_type IN (202,204,207,211,212,213,214,215,216,221,222,236)),0)* 8 as ReservedKb
,IsNull((Select SUM(in_row_data_page_count + lob_used_page_count + row_overflow_used_page_count)
from sys.dm_db_partition_stats p with(nolock) where p.object_id=t.object_id and p.index_id < 2),0)* 8 as TableUsedKb
,IsNull((Select SUM(used_page_count) from sys.dm_db_partition_stats p with(nolock) where p.object_id=t.object_id),0)*8
+ IsNull((Select sum(used_page_count)
FROM sys.dm_db_partition_stats p2 with(nolock)
inner join sys.internal_tables it with(nolock) on p2.object_id = it.object_id
WHERE it.parent_id = t.object_id
AND it.internal_type IN (202,204,207,211,212,213,214,215,216,221,222,236)),0)* 8 as UsedKb
,create_date
,modify_date
from sys.tables t with(nolock)
where Type='U'
) A
order by ReservedKb desc