Hola Juan Vidal IT:
Lo primero, es que tener mucha memoria, evidentemente, irá en benefició del la velocidad de la aplicación en tanto en cuanto se consuman datos. Pero si presenta problemas de lentitud, hay que diferenciar un poco si la lentitud es por cantidad de memoria,
por procesamiento, o por problemas derivados de la red, o lecturas en disco. Todo esto atribuyendo el empeoramiento al sql, que quizá no sea el culpable.
Si puedes ejecutar consultas:
select
(physical_memory_in_use_kb/1024)Phy_Memory_usedby_Sqlserver_MB,
(locked_page_allocations_kb/1024 )Locked_pages_used_Sqlserver_MB,
(virtual_address_space_committed_kb/1024 )Total_Memory_UsedBySQLServer_MB,
process_physical_memory_low,
process_virtual_memory_low
from sys. dm_os_process_memory
Mucho más detallado y elaborado:
https://github.com/ktaranov/sqlserver-kit/blob/master/Scripts/SQLServer_Memory_Information.sql
SET NOCOUNT ON;
SET TRANSACTION ISOLATION LEVEL READ UNCOMMITTED;
SET LOCK_TIMEOUT 10000;
DECLARE @ServiceName nvarchar(100);
SET @ServiceName =
CASE
WHEN @@SERVICENAME = 'MSSQLSERVER' THEN 'SQLServer:'
ELSE 'MSSQL$' + @@SERVICENAME + ':'
END;
DECLARE @Perf TABLE (
object_name nvarchar(20),
counter_name nvarchar(128),
instance_name nvarchar(128),
cntr_value bigint,
formatted_value numeric(20, 2),
shortname nvarchar(20)
);
INSERT INTO @Perf (object_name, counter_name, instance_name, cntr_value, formatted_value, shortname)
SELECT
CASE
WHEN CHARINDEX('Memory Manager', object_name) > 0 THEN 'Memory Manager'
WHEN CHARINDEX('Buffer Manager', object_name) > 0 THEN 'Buffer Manager'
WHEN CHARINDEX('Plan Cache', object_name) > 0 THEN 'Plan Cache'
WHEN CHARINDEX('Buffer Node', object_name) > 0 THEN 'Buffer Node' -- 2008
WHEN CHARINDEX('Memory Node', object_name) > 0 THEN 'Memory Node' -- 2012
WHEN CHARINDEX('Cursor', object_name) > 0 THEN 'Cursor'
ELSE NULL
END AS object_name,
CAST(RTRIM(counter_name) AS nvarchar(100)) AS counter_name,
RTRIM(instance_name) AS instance_name,
cntr_value,
CAST(NULL AS decimal(20, 2)) AS formatted_value,
SUBSTRING(counter_name, 1, PATINDEX('% %', counter_name)) shortname
FROM sys.dm_os_performance_counters
WHERE (object_name LIKE @ServiceName + 'Buffer Node%' -- LIKE is faster than =. I have no idea why
OR object_name LIKE @ServiceName + 'Buffer Manager%'
OR object_name LIKE @ServiceName + 'Memory Node%'
OR object_name LIKE @ServiceName + 'Plan Cache%')
AND (counter_name LIKE '%pages %'
OR counter_name LIKE '%Node Memory (KB)%'
OR counter_name = 'Page life expectancy'
)
OR (object_name = @ServiceName + 'Memory Manager'
AND counter_name IN ('Granted Workspace Memory (KB)', 'Maximum Workspace Memory (KB)',
'Memory Grants Outstanding', 'Memory Grants Pending',
'Target Server Memory (KB)', 'Total Server Memory (KB)',
'Connection Memory (KB)', 'Lock Memory (KB)',
'Optimizer Memory (KB)', 'SQL Cache Memory (KB)',
-- for 2012
'Free Memory (KB)', 'Reserved Server Memory (KB)',
'Database Cache Memory (KB)', 'Stolen Server Memory (KB)')
)
OR (object_name LIKE @ServiceName + 'Cursor Manager by Type%'
AND counter_name = 'Cursor memory usage'
AND instance_name = '_Total'
);
-- Add unit to 'Cursor memory usage'
UPDATE @Perf
SET counter_name = counter_name + ' (KB)'
WHERE counter_name = 'Cursor memory usage';
-- Convert values from pages and KB to MB and rename counters accordingly
UPDATE @Perf
SET counter_name = REPLACE(REPLACE(REPLACE(counter_name, ' pages', ''), ' (KB)', ''), ' (MB)', ''),
formatted_value =
CASE
WHEN counter_name LIKE '%pages' THEN cntr_value / 128.
WHEN counter_name LIKE '%(KB)' THEN cntr_value / 1024.
ELSE cntr_value
END;
-- Delete some pre 2012 counters for 2012 in order to remove duplicates
DELETE P2008
FROM @Perf P2008
INNER JOIN @Perf P2012
ON REPLACE(P2008.object_name, 'Buffer', 'Memory') = P2012.object_name
AND P2008.shortname = P2012.shortname
WHERE P2008.object_name IN ('Buffer Manager', 'Buffer Node');
-- Update counter/object names so they look like in 2012
UPDATE PC
SET object_name = REPLACE(object_name, 'Buffer', 'Memory'),
counter_name = ISNULL(M.NewName, counter_name)
FROM @Perf PC
LEFT JOIN (SELECT
'Free' AS OldName,
'Free Memory' AS NewName
UNION ALL
SELECT
'Database',
'Database Cache Memory'
UNION ALL
SELECT
'Stolen',
'Stolen Server Memory'
UNION ALL
SELECT
'Reserved',
'Reserved Server Memory'
UNION ALL
SELECT
'Foreign',
'Foreign Node Memory') M
ON M.OldName = PC.counter_name
AND NewName NOT IN (SELECT
counter_name
FROM @Perf
WHERE object_name = 'Memory Manager')
WHERE object_name IN ('Buffer Manager', 'Buffer Node');
-- Build Memory Tree
DECLARE @MemTree TABLE (
Id int,
ParentId int,
counter_name nvarchar(128),
formatted_value numeric(20, 2),
shortname nvarchar(20)
);
-- Level 5
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id = 1226,
ParentId = 1225,
instance_name AS counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Plan Cache'
AND counter_name IN ('Cache')
AND instance_name <> '_Total';
-- Level 4
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id = 1225,
ParentId = 1220,
'Plan ' + counter_name AS counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Plan Cache'
AND counter_name IN ('Cache')
AND instance_name = '_Total'
UNION ALL
SELECT
Id = 1222,
ParentId = 1220,
counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Cursor'
OR (object_name = 'Memory Manager'
AND shortname IN ('Connection', 'Lock', 'Optimizer', 'SQL'))
UNION ALL
SELECT
Id = 1112,
ParentId = 1110,
counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Memory Manager'
AND shortname IN ('Reserved')
UNION ALL
SELECT
Id = P.ParentID + 1,
ParentID = P.ParentID,
'Used Workspace Memory' AS counter_name,
SUM(used_memory_kb) / 1024. AS formatted_value,
NULL AS shortname
FROM sys.dm_exec_query_resource_semaphores
CROSS JOIN (SELECT
1220 AS ParentID
UNION ALL
SELECT
1110) P
GROUP BY P.ParentID;
-- Level 3
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id =
CASE counter_name
WHEN 'Granted Workspace Memory' THEN 1110
WHEN 'Stolen Server Memory' THEN 1220
ELSE 1210
END,
ParentId =
CASE counter_name
WHEN 'Granted Workspace Memory' THEN 1100
ELSE 1200
END,
counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Memory Manager'
AND counter_name IN ('Stolen Server Memory', 'Database Cache Memory', 'Free Memory', 'Granted Workspace Memory');
-- Level 2
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id =
CASE
WHEN counter_name = 'Maximum Workspace Memory' THEN 1100
ELSE 1200
END,
ParentId = 1000,
counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Memory Manager'
AND counter_name IN ('Total Server Memory', 'Maximum Workspace Memory');
-- Level 1
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id = 1000,
ParentId = NULL,
counter_name,
formatted_value,
shortname
FROM @Perf
WHERE object_name = 'Memory Manager'
AND counter_name IN ('Target Server Memory');
-- Level 4 -- 'Other Stolen Server Memory' = 'Stolen Server Memory' - SUM(Children of 'Stolen Server Memory')
INSERT @MemTree (Id, ParentId, counter_name, formatted_value, shortname)
SELECT
Id = 1222,
ParentId = 1220,
counter_name = '<Other Memory Clerks>',
formatted_value = (SELECT
SSM.formatted_value
FROM @MemTree SSM
WHERE Id = 1220)
- SUM(formatted_value),
shortname = 'Other Stolen'
FROM @MemTree
WHERE ParentId = 1220;
-- Results:
-- PLE and Memory Grants
SELECT
[Counter Name] = P.counter_name + ISNULL(' (Node: ' + NULLIF(P.instance_name, '') + ')', ''),
cntr_value AS Value,
RecommendedMinimum =
CASE
WHEN P.counter_name = 'Page life expectancy' AND
R.Value <= 300 -- no less than 300
THEN 300
WHEN P.counter_name = 'Page life expectancy' AND
R.Value > 300 THEN R.Value
ELSE NULL
END
FROM @Perf P
LEFT JOIN -- Recommended PLE calculations
(SELECT
object_name,
counter_name,
instance_name,
CEILING(formatted_value / 4096. * 5) * 60 AS Value -- 300 per every 4GB of Buffer Pool memory or around 60 seconds (1 minute) per every 819MB
FROM @Perf PD
WHERE counter_name = 'Database Cache Memory') R
ON R.object_name = P.object_name
AND R.instance_name = P.instance_name
WHERE (P.object_name = 'Memory Manager'
AND P.counter_name IN ('Memory Grants Outstanding', 'Memory Grants Pending', 'Page life expectancy')
)
OR -- For NUMA
(
P.object_name = 'Memory Node'
AND P.counter_name = 'Page life expectancy'
AND (SELECT
COUNT(DISTINCT instance_name)
FROM @Perf
WHERE object_name = 'Memory Node')
> 1
)
ORDER BY P.counter_name DESC, P.instance_name;
-- Get physical memory
-- You can also extract this information from sys.dm_os_sys_info but the column names have changed starting from 2012
IF OBJECT_ID('tempdb..#msver') IS NOT NULL
DROP TABLE #msver
CREATE TABLE #msver (
ID int,
Name sysname,
Internal_Value int,
Value nvarchar(512)
);
INSERT #msver EXEC master.dbo.xp_msver 'PhysicalMemory';
-- Physical memory, config parameters and Target memory
SELECT
min_server_mb = (SELECT
CAST(value_in_use AS decimal(20, 2))
FROM sys.configurations
WHERE name = 'min server memory (MB)'),
max_server_mb = (SELECT
CAST(value_in_use AS decimal(20, 2))
FROM sys.configurations
WHERE name = 'max server memory (MB)'),
target_mb = (SELECT
formatted_value
FROM @Perf
WHERE object_name = 'Memory Manager'
AND counter_name IN ('Target Server Memory')),
physical_mb = CAST(Internal_Value AS decimal(20, 2))
FROM #msver;
-- Memory tree
;
WITH CTE
AS (SELECT
0 AS lvl,
counter_name,
formatted_value,
Id,
NULL AS ParentId,
shortname,
formatted_value AS TargetServerMemory,
CAST(NULL AS decimal(20, 4)) AS Perc,
CAST(NULL AS decimal(20, 4)) AS PercOfTarget
FROM @MemTree
WHERE ParentId IS NULL
UNION ALL
SELECT
CTE.lvl + 1,
CAST(REPLICATE(' ', 6 * (CTE.lvl)) + NCHAR(124) + REPLICATE(NCHAR(183), 3) + MT.counter_name AS nvarchar(128)),
MT.formatted_value,
MT.Id,
MT.ParentId,
MT.shortname,
CTE.TargetServerMemory,
CAST(ISNULL(1.0 * MT.formatted_value / NULLIF(CTE.formatted_value, 0), 0) AS decimal(20, 4)) AS Perc,
CAST(ISNULL(1.0 * MT.formatted_value / NULLIF(CTE.TargetServerMemory, 0), 0) AS decimal(20, 4)) AS PercOfTarget
FROM @MemTree MT
INNER JOIN CTE
ON MT.ParentId = CTE.Id)
SELECT
counter_name AS [Counter Name],
CASE
WHEN formatted_value > 0 THEN formatted_value
ELSE NULL
END AS [Memory MB],
Perc AS [% of Parent],
CASE
WHEN lvl >= 2 THEN PercOfTarget
ELSE NULL
END AS [% of Target]
FROM CTE
ORDER BY ISNULL(Id, 10000), formatted_value DESC;
Pero muchas bases de datos, de Sql Server, (ediciones express), sirven datos, a una velocidad muy buena con un giga de ram, para aplicaciones de empresas no muy grandes, que no necesiten un volumen de datos grande.
Por tanto si la demora es al realizar cosas sencillas (volumén de datos pequeño), no tiene que ver el uso de la memoria.
Lentitud en apliacion que usa SQL 2014
PROCESOS, ESPERAS DE RECURSOS, E/S DE ARCHIVOS DE DATOS, CONSULTAS COSTOSAS RECIENTES, CONSULTAS COSTOSAS ACTIVAS
