sp_MStablespace (Transact-SQL MetaData) Definition

Please note: that the following source code is provided and copyrighted by Microsoft and is for educational purpose only.
The meta data is from an SQL 2012 Server.

I have posted alot more, find the whole list here.

Goto Definition or MetaData

Definition:

sys.sp_MStablespace(nvarchar @name
, int @id)

MetaData:

   
create procedure sys.sp_MStablespace  
@name nvarchar(517), @id int = null  
as  
    declare @rows int, @datasizeused int, @indexsizeused int, @pagesize int  
    declare @dbname nvarchar(128)  
    select @dbname = db_name()  
  
    if (@id is null)  
        select @id = id from dbo.sysobjects where id = object_id(@name) and (OBJECTPROPERTY(id, N'IsTable') = 1)  
    if (@id is null)  
    begin  
        RAISERROR (15009, -1, -1, @name, @dbname)  
        return 1  
    end  
  
    --  rows  --   
    SELECT @rows = convert(int, rowcnt)  
        FROM dbo.sysindexes  
        WHERE indid < 2 and id = @id  
  
    if (object_id('master.dbo.sp_MSSQLDMO90_version') is not null)  
    BEGIN  
  
        --  data  --   
        SELECT @datasizeused =  
            SUM(CASE WHEN a.type <> 1 THEN a.used_pages   
                    WHEN p.index_id < 2 THEN a.data_pages   
                    ELSE 0   
                END)   
        FROM sys.indexes as i  
        JOIN sys.partitions as p ON p.object_id = i.object_id and p.index_id = i.index_id  
        JOIN sys.allocation_units as a ON a.container_id = p.partition_id  
        where i.object_id = @id  
  
        --  index  --   
        SELECT @indexsizeused =   
            sum(isnull(sidx.used,0)-isnull(sidx.dpages,0))  
            FROM dbo.sysindexes sidx  
            WHERE sidx.indid < 2 and sidx.id = @id  
    END  
    ELSE  
    BEGIN  
        --  data  --   
        SELECT @datasizeused =  
        (SELECT sum(dpages)  
        FROM dbo.sysindexes  
        WHERE indid < 2 and id = @id)  
        +  
        (SELECT isnull(sum(used), 0)  
        FROM dbo.sysindexes  
        WHERE indid = 255 and id = @id)  
  
        --  Do not consider 2 < indid < 255 rows, those are nonclustered indices, and the space used by them are included by indid = 0(table)  --   
        --  or indid = 1(clustered index) already.  indid = 0(table) and = 1(clustered index) are mutual exclusive  --   
        --  index  --   
        SELECT @indexsizeused =  
        (SELECT sum(used)  
        FROM dbo.sysindexes  
        WHERE indid in (0, 1, 255) and id = @id)  
        - @datasizeused  
    END  
  
    --  Pagesize on this server (sysindexes stores size info in pages)  --   
    select @pagesize = v.low / 1024 from master..spt_values v where v.number=1 and v.type=N'E'  
  
    select Rows = @rows, DataSpaceUsed = @datasizeused * @pagesize, IndexSpaceUsed = @indexsizeused * @pagesize