Today's script is a collection of a few memory queries I've collected from various sources over the years. These queries are by no means comprehensive but are ones I have certainly used the most.
/*
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Memory Queries
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*/
-- Interrogating memory configuration.
-- Determine if this is a 32- or 64-bit SQL Server edition
DECLARE @ServerAddressing AS TINYINT
SELECT @serverAddressing = CASE WHEN CHARINDEX('64',
CAST(SERVERPROPERTY('Edition')
AS VARCHAR(100))) > 0
THEN 64
ELSE 32
END ;
SELECT cpu_count / hyperthread_ratio AS SocketCount ,
physical_memory_in_bytes / 1024 / 1024 AS physical_memory_mb ,
virtual_memory_in_bytes / 1024 / 1024 AS sql_max_virtual_memory_mb ,
-- same with other bpool columns as they are page oriented.
-- Multiplying by 8 takes it to 8K, then / 1024 to convert to mb
bpool_committed * 8 / 1024 AS buffer_pool_committed_mb ,
--64 bit OS does not have limitations with addressing as 32 did
CASE WHEN @serverAddressing = 32
THEN CASE WHEN virtual_memory_in_bytes / 1024 /
( 2048 * 1024 ) < 1
THEN 'off'
ELSE 'on'
END
ELSE 'N/A on 64 bit'
END AS [/3GB switch]
FROM sys.dm_os_sys_info
-- Is NUMA enabled
SELECT CASE COUNT(DISTINCT parent_node_id)
WHEN 1 THEN 'NUMA disabled'
ELSE 'NUMA enabled'
END
FROM sys.dm_os_schedulers
WHERE parent_node_id <> 32 ;
-- Show memory consumption details
DBCC MEMORYSTATUS
-- System memory usage.
SELECT total_physical_memory_kb / 1024 AS total_physical_memory_mb,
available_physical_memory_kb / 1024 AS available_physical_memory_mb,
total_page_file_kb / 1024 AS total_page_file_mb,
available_page_file_kb / 1024 AS available_page_file_mb,
system_memory_state_desc
FROM sys.dm_os_sys_memory
-- Memory usage by the SQL Server process.
SELECT physical_memory_in_use_kb,
virtual_address_space_committed_kb,
virtual_address_space_available_kb,
page_fault_count,
process_physical_memory_low,
process_virtual_memory_low
FROM sys.dm_os_process_memory
-- Get total buffer usage by database
SELECT DB_NAME(database_id) AS [Database Name],
COUNT(*) * 8 / 1024.0 AS [Cached Size (MB)]
FROM sys.dm_os_buffer_descriptors
WHERE database_id > 4 -- exclude system databases
AND database_id <> 32767 -- exclude ResourceDB
GROUP BY DB_NAME(database_id)
ORDER BY [Cached Size (MB)] DESC ;
-- Breaks down buffers by object (table, index) in the buffer pool
SELECT OBJECT_NAME(p.[object_id]) AS [ObjectName],
p.index_id,
COUNT(*) / 128 AS [Buffer size(MB)],
COUNT(*) AS [Buffer_count]
FROM sys.allocation_units AS a
INNER JOIN sys.dm_os_buffer_descriptors AS b ON a.allocation_unit_id = b.allocation_unit_id
INNER JOIN sys.partitions AS p ON a.container_id = p.hobt_id
WHERE b.database_id = DB_ID() -- Change to suit
AND p.[object_id] > 100 -- exclude system objects
GROUP BY p.[object_id],
p.index_id
ORDER BY buffer_count DESC ;
-- Buffer Pool Usage for instance
SELECT TOP ( 20 )
[type],
SUM(single_pages_kb) AS [SPA Mem, Kb]
FROM sys.dm_os_memory_clerks
GROUP BY [type]
ORDER BY SUM(single_pages_kb) DESC ;
-- Which queries have requested, or have had to wait for, large memory grants?
-- Shows the memory required by both running (non-null grant_time)
-- and waiting queries (null grant_time)
-- SQL Server 2008 version
SELECT DB_NAME(st.[dbid]) AS [DatabaseName],
mg.requested_memory_kb,
mg.ideal_memory_kb,
mg.request_time,
mg.grant_time,
mg.query_cost,
mg.dop,
st.[text]
FROM sys.dm_exec_query_memory_grants AS mg
CROSS APPLY sys.dm_exec_sql_text(plan_handle) AS st
WHERE mg.request_time < COALESCE(grant_time, '99991231')
ORDER BY mg.requested_memory_kb DESC ;
-- Shows the memory required by both running (non-null grant_time)
-- and waiting queries (null grant_time)
-- SQL Server 2005 version
SELECT DB_NAME(st.[dbid]) AS [DatabaseName],
mg.requested_memory_kb,
mg.request_time,
mg.grant_time,
mg.query_cost,
mg.dop,
st.[text]
FROM sys.dm_exec_query_memory_grants AS mg
CROSS APPLY sys.dm_exec_sql_text(plan_handle) AS st
WHERE mg.request_time < COALESCE(grant_time, '99991231')
ORDER BY mg.requested_memory_kb DESC ;
-- Return the cache counters.
SELECT [type],
name,
single_pages_kb,
multi_pages_kb,
single_pages_in_use_kb,
multi_pages_in_use_kb,
entries_count,
entries_in_use_count
FROM sys.dm_os_memory_cache_counters
ORDER BY [type],
name ;
-- Investigating the use of the plan cache.
SELECT name,
[type],
entries_count,
entries_in_use_count
FROM sys.dm_os_memory_cache_counters
WHERE [type] IN ( 'CACHESTORE_SQLCP', 'CACHESTORE_OBJCP' )
--ad hoc plans and object plans
ORDER BY name,
[type]
-- AWE allocated memory
SELECT SUM(awe_allocated_kb) / 1024 AS [AWE allocated, Mb]
FROM sys.dm_os_memory_clerks
-- Single + Multi Page Memory Allocation
SELECT type,
SUM(virtual_memory_reserved_kb) AS [VM Reserved],
SUM(virtual_memory_committed_kb) AS [VM Committed],
SUM(awe_allocated_kb) AS [AWE Allocated],
SUM(shared_memory_reserved_kb) AS [SM Reserved],
SUM(shared_memory_committed_kb) AS [SM Committed],
SUM(multi_pages_kb) AS [MultiPage Allocator],
SUM(single_pages_kb) AS [SinlgePage Allocator]
FROM sys.dm_os_memory_clerks
GROUP BY type
-- amount of mem allocated though multipage allocator interface
SELECT SUM(multi_pages_kb)
FROM sys.dm_os_memory_clerks
-- amount of mem allocated though multipage allocator interface DETAILED
SELECT type,
SUM(multi_pages_kb) AS sizeinkb
FROM sys.dm_os_memory_clerks
WHERE multi_pages_kb != 0
GROUP BY type
-- Detailed memory info per componant
DECLARE @total_alloc BIGINT
DECLARE @tab TABLE
(
type NVARCHAR(128) COLLATE database_default,
allocated BIGINT,
virtual_res BIGINT,
virtual_com BIGINT,
awe BIGINT,
shared_res BIGINT,
shared_com BIGINT,
topFive NVARCHAR(128),
grand_total BIGINT
) ;
-- note that this total excludes buffer pool committed memory as it represents the largest
-- consumer which is normal
SELECT @total_alloc = SUM(single_pages_kb + multi_pages_kb
+ ( CASE WHEN type <> 'MEMORYCLERK_SQLBUFFERPOOL'
THEN virtual_memory_committed_kb
ELSE 0
END ) + shared_memory_committed_kb)
FROM sys.dm_os_memory_clerks
PRINT 'Total allocated (including from Buffer Pool): '
+ CAST(@total_alloc AS VARCHAR(10)) + ' Kb'
INSERT INTO @tab
SELECT type,
SUM(single_pages_kb + multi_pages_kb) AS allocated,
SUM(virtual_memory_reserved_kb) AS vertual_res,
SUM(virtual_memory_committed_kb) AS virtual_com,
SUM(awe_allocated_kb) AS awe,
SUM(shared_memory_reserved_kb) AS shared_res,
SUM(shared_memory_committed_kb) AS shared_com,
CASE WHEN ( ( SUM(single_pages_kb + multi_pages_kb
+ ( CASE WHEN type <> 'MEMORYCLERK_SQLBUFFERPOOL'
THEN virtual_memory_committed_kb
ELSE 0
END ) + shared_memory_committed_kb) )
/ ( @total_alloc + 0.0 ) ) >= 0.05 THEN type
ELSE 'Other'
END AS topFive,
( SUM(single_pages_kb + multi_pages_kb
+ ( CASE WHEN type <> 'MEMORYCLERK_SQLBUFFERPOOL'
THEN virtual_memory_committed_kb
ELSE 0
END ) + shared_memory_committed_kb) ) AS grand_total
FROM sys.dm_os_memory_clerks
GROUP BY type
ORDER BY ( SUM(single_pages_kb + multi_pages_kb
+ ( CASE WHEN type <> 'MEMORYCLERK_SQLBUFFERPOOL'
THEN virtual_memory_committed_kb
ELSE 0
END ) + shared_memory_committed_kb) ) DESC
SELECT *
FROM @tab
Enjoy!
Chris
