090. SQL Server Script to check the Allocation Units of a Table

--********* 090. SQL Server Script to check the Allocation Units of a Table
--Reference : https://www.sqlskills.com/


DECLARE @object SYSNAME = 'table_name'
 
SELECT
    OBJECT_NAME ([sp].[object_id]) AS [Object Name],
    [sp].[index_id] AS [Index ID],
    [sp].[partition_id] AS [Partition ID],
        [sa].[allocation_unit_id] AS [Alloc Unit ID],
    [sa].[type_desc] AS [Alloc Unit Type],
    '(' + CONVERT (VARCHAR (6),
        CONVERT (INT,
            SUBSTRING ([sa].[first_page], 6, 1) +
            SUBSTRING ([sa].[first_page], 5, 1))) +
    ':' + CONVERT (VARCHAR (20),
        CONVERT (INT,
            SUBSTRING ([sa].[first_page], 4, 1) +
            SUBSTRING ([sa].[first_page], 3, 1) +
            SUBSTRING ([sa].[first_page], 2, 1) +
            SUBSTRING ([sa].[first_page], 1, 1))) +
    ')' AS [First Page],
    '(' + CONVERT (VARCHAR (6),
        CONVERT (INT,
            SUBSTRING ([sa].[root_page], 6, 1) +
            SUBSTRING ([sa].[root_page], 5, 1))) +
    ':' + CONVERT (VARCHAR (20),
        CONVERT (INT,
            SUBSTRING ([sa].[root_page], 4, 1) +
            SUBSTRING ([sa].[root_page], 3, 1) +
            SUBSTRING ([sa].[root_page], 2, 1) +
            SUBSTRING ([sa].[root_page], 1, 1))) +
    ')' AS [Root Page],
    '(' + CONVERT (VARCHAR (6),
        CONVERT (INT,
            SUBSTRING ([sa].[first_iam_page], 6, 1) +
            SUBSTRING ([sa].[first_iam_page], 5, 1))) +
    ':' + CONVERT (VARCHAR (20),
        CONVERT (INT,
            SUBSTRING ([sa].[first_iam_page], 4, 1) +
            SUBSTRING ([sa].[first_iam_page], 3, 1) +
            SUBSTRING ([sa].[first_iam_page], 2, 1) +
            SUBSTRING ([sa].[first_iam_page], 1, 1))) +
    ')' AS [First IAM Page]
FROM
    sys.system_internals_allocation_units AS [sa],
    sys.partitions AS [sp]
WHERE
    [sa].[container_id] = [sp].[partition_id]
AND [sp].[object_id] =
(CASE WHEN (@object IS NULL)
    THEN [sp].[object_id]
    ELSE OBJECT_ID (@object)
END)