Determine row size for table

问题:

How to I determine the maximum row size for a table? I'm looking for a tool or script that does this so I don't have to add up each column's size by hand.

My goal is to produce a report of tables that are too wide so we can look into restructing them. I know we have several that are so wide that only 1 row fits on each 8K page, but I want to find the rest.

回答1:

Another way, run this then look at MaximumRecordsize

dbcc showcontig ('YourTableNameHere') with tableresults

回答2:

As the DBCC SHOWCONTIG is going to be deprecated, Microsoft advises to use the sys.dm_db_index_physical_stats instead. You can get the maximum, minimum and average row size for each index and other stats, too:

SELECT * FROM sys.dm_db_index_physical_stats (DB_ID(N'AdventureWorks2014'), OBJECT_ID(N'[sales].[SalesOrderHeader]'), NULL, NULL , 'DETAILED')

Output:

database_id object_id   index_id    partition_number index_type_desc                                              alloc_unit_type_desc                                         index_depth index_level avg_fragmentation_in_percent fragment_count       avg_fragment_size_in_pages page_count           avg_page_space_used_in_percent record_count         ghost_record_count   version_ghost_record_count min_record_size_in_bytes max_record_size_in_bytes avg_record_size_in_bytes forwarded_record_count compressed_page_count
----------- ----------- ----------- ---------------- ------------------------------------------------------------ ------------------------------------------------------------ ----------- ----------- ---------------------------- -------------------- -------------------------- -------------------- ------------------------------ -------------------- -------------------- -------------------------- ------------------------ ------------------------ ------------------------ ---------------------- ---------------------
6           1266103551  1           1                CLUSTERED INDEX                                              IN_ROW_DATA                                                  3           0           0.439882697947214            28                   24.3571428571429           682                  98.8644304423029               31465                0                    0                          154                      195                      171.487                  NULL                   0
6           1266103551  1           1                CLUSTERED INDEX                                              IN_ROW_DATA                                                  3           1           0                            2                    1                          2                    54.7442550037064               682                  0                    0                          11                       11                       11                       NULL                   0
6           1266103551  1           1                CLUSTERED INDEX                                              IN_ROW_DATA                                                  3           2           0                            1                    1                          1                    0.296515937731653              2                    0                    0                          11                       11                       11                       NULL                   0
6           1266103551  2           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           0           0                            4                    25.5                       102                  99.0670990857425               31465                0                    0                          24                       24                       24                       NULL                   0
6           1266103551  2           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           1           0                            1                    1                          1                    31.4801087225105               102                  0                    0                          23                       23                       23                       NULL                   0
6           1266103551  3           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           0           0                            3                    36.3333333333333           109                  99.8363355572029               31465                0                    0                          26                       26                       26                       NULL                   0
6           1266103551  3           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           1           0                            1                    1                          1                    36.3355572028663               109                  0                    0                          25                       25                       25                       NULL                   0
6           1266103551  4           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           0           0                            2                    27.5                       55                   98.9285025945145               31465                0                    0                          12                       12                       12                       NULL                   0
6           1266103551  4           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           1           0                            1                    1                          1                    11.527057079318                55                   0                    0                          15                       15                       15                       NULL                   0
6           1266103551  5           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           0           0                            2                    27.5                       55                   98.9285025945145               31465                0                    0                          12                       12                       12                       NULL                   0
6           1266103551  5           1                NONCLUSTERED INDEX                                           IN_ROW_DATA                                                  2           1           0                            1                    1                          1                    13.5656041512231               55                   0                    0                          18                       18                       18                       NULL                   0

回答3:

Here is another query I got, but like Tomalak's it is broken because it doesn't take into account things like the overhead for variable length columns.

SELECT OBJECT_NAME (id) tablename
     , COUNT (1)        nr_columns
     , SUM (length)     maxrowlength
FROM   syscolumns
GROUP BY OBJECT_NAME (id)
ORDER BY OBJECT_NAME (id)

回答4:

Have a look at INFORMATION_SCHEMA.COLUMNS. You can add the size of each column in a table to give you an idea which tables have the potential to overshoot the 8k/row rule.

SELECT * FROM INFORMATION_SCHEMA.COLUMNS 

You will figure out the rest when you see the query result.

回答5:

Might not the best but this is showing the number of rows + for columns with datatype date,time and so on

SELECT 
    t.NAME AS TableName,
    s.Name AS SchemaName,
    p.rows AS RowCounts,
    SUM(a.total_pages) * 8 AS TotalSpaceKB, 
    CAST(ROUND(((SUM(a.total_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS TotalSpaceMB,
    SUM(a.used_pages) * 8 AS UsedSpaceKB, 
    CAST(ROUND(((SUM(a.used_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS UsedSpaceMB, 
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB,
    CAST(ROUND(((SUM(a.total_pages) - SUM(a.used_pages)) * 8) / 1024.00, 2) AS NUMERIC(36, 2)) AS UnusedSpaceMB
FROM 
    sys.tables t
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
LEFT OUTER JOIN 
    sys.schemas s ON t.schema_id = s.schema_id
INNER JOIN  sysobjects so on t.object_id = so.id
INNER JOIN  syscolumns SC on (so.id = sc.id)
INNER JOIN systypes st on (st.type = sc.type)
WHERE 
    t.NAME NOT LIKE 'dt%' 
    AND t.is_ms_shipped = 0
    AND i.OBJECT_ID > 255 
    AND so.type = 'U'
and st.name IN ('DATETIME', 'DATE', 'TIME')
GROUP BY 
    t.Name, s.Name, p.Rows
ORDER BY 
    p.rows DESC

回答6:

Better option to get table size

SELECT 
    t.NAME AS TableName,
    s.Name AS SchemaName,
    p.rows AS RowCounts,
    SUM(a.total_pages) * 8 AS TotalSpaceKB, 
    CAST(ROUND(((SUM(a.total_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS TotalSpaceMB,
    SUM(a.used_pages) * 8 AS UsedSpaceKB, 
    CAST(ROUND(((SUM(a.used_pages) * 8) / 1024.00), 2) AS NUMERIC(36, 2)) AS UsedSpaceMB, 
    (SUM(a.total_pages) - SUM(a.used_pages)) * 8 AS UnusedSpaceKB,
    CAST(ROUND(((SUM(a.total_pages) - SUM(a.used_pages)) * 8) / 1024.00, 2) AS NUMERIC(36, 2)) AS UnusedSpaceMB
FROM 
    sys.tables t
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
LEFT OUTER JOIN 
    sys.schemas s ON t.schema_id = s.schema_id
WHERE 
    t.NAME NOT LIKE 'dt%' 
    AND t.is_ms_shipped = 0
    AND i.OBJECT_ID > 255 
GROUP BY 
    t.Name, s.Name, p.Rows
ORDER BY 
    t.Name