How to find memory usage by table? [duplicate]

Question

I want to discover how much memory is being used by each table. Is this information available in DMVs or elsewhere?

Answer 1

what you can do is

1. Find out the database that consumes highest memory in buffer pool using below :

   SELECT COUNT(*) AS cached_pages_count , 
       ( COUNT(*) * 8.0 ) / 1024 AS MB , 
       CASE database_id 
         WHEN 32767 THEN 'ResourceDb' 
         ELSE DB_NAME(database_id) 
       END AS Database_name 
   FROM sys.dm_os_buffer_descriptors 
   GROUP BY database_id
   

2. Drill down the database using below query :

   set nocount on;
   set transaction isolation level read uncommitted;
   select
      count(*)as cached_pages_count,
      (COUNT(*) * 8.0) / 1024 AS Total_MB_Occupied, -- convert pages into MB -  the page size is 8 KB for sql server
      obj.name as objectname,
      ind.name as indexname,
      obj.index_id as indexid
   from sys.dm_os_buffer_descriptors as bd
   inner join
   (
       select       object_id as objectid,
                          object_name(object_id) as name,
                          index_id,allocation_unit_id
       from sys.allocation_units as au
           inner join sys.partitions as p
               on au.container_id = p.hobt_id
                   and (au.type = 1 or au.type = 3)
       union all
       select       object_id as objectid,
                          object_name(object_id) as name,
                          index_id,allocation_unit_id
       from sys.allocation_units as au
           inner join sys.partitions as p
               on au.container_id = p.partition_id
                   and au.type = 2
   ) as obj
       on bd.allocation_unit_id = obj.allocation_unit_id
   left outer join sys.indexes ind 
   on  obj.objectid = ind.object_id
   and  obj.index_id = ind.index_id
   where bd.database_id = db_id()
   and bd.page_type in ('data_page', 'index_page')
   group by obj.name, ind.name, obj.index_id
   order by cached_pages_count desc
   

Reference :

• A quick look at: sys.dm_os_buffer_descriptors
• What's swimming in your bufferpool?
• sys.dm_os_buffer_descriptors aggregations -- more detailed info - what objects/structures/files/etc. are consuming the largest amount of space at a given time (or over time) within the Sql Server buffer pool.

Answer 2

From my tip here:

;WITH src AS
(
   SELECT
       [Object] = o.name,
       [Type] = o.type_desc,
       [Index] = COALESCE(i.name, ''),
       [Index_Type] = i.type_desc,
       p.[object_id],
       p.index_id,
       au.allocation_unit_id
   FROM sys.partitions AS p
   INNER JOIN sys.allocation_units AS au
       ON p.hobt_id = au.container_id
   INNER JOIN sys.objects AS o
       ON p.[object_id] = o.[object_id]
   INNER JOIN sys.indexes AS i
       ON o.[object_id] = i.[object_id]
       AND p.index_id = i.index_id
   WHERE au.[type] IN (1,2,3) AND o.is_ms_shipped = 0
)
SELECT
   src.[Object],
   src.[Type],
   src.[Index],
   src.Index_Type,
   buffer_pages = COUNT_BIG(b.page_id),
   buffer_mb = COUNT_BIG(b.page_id) / 128
FROM src
INNER JOIN
   sys.dm_os_buffer_descriptors AS b
   ON src.allocation_unit_id = b.allocation_unit_id
WHERE b.database_id = DB_ID()
GROUP BY
   src.[Object],
   src.[Type],
   src.[Index],
   src.Index_Type
ORDER BY
   buffer_pages DESC;