SQL Server's buffer pool cache is designed to aggressively acquire memory and maintain it until the operating system explicitly requests it back. This behavior becomes particularly problematic in virtualized environments where other VMs might need those resources. The fundamental issue isn't that SQL Server won't release memory - it's about understanding the triggers that make it actually release memory.

SQL Server divides its memory usage into several components:

-- Check current memory allocation
SELECT 
    physical_memory_in_use_kb/1024 AS [SQL Server Memory Usage (MB)],
    locked_page_allocations_kb/1024 AS [Locked Pages Allocation (MB)],
    large_page_allocations_kb/1024 AS [Large Page Allocation (MB)],
    virtual_address_space_committed_kb/1024 AS [Committed Memory (MB)]
FROM sys.dm_os_process_memory;

Instead of waiting for Windows memory pressure, consider these approaches:

1. DBCC FREEPROCCACHE with Controlled Parameters

-- Release specific cache types without flushing everything
DBCC FREESYSTEMCACHE ('SQL Plans');
DBCC FREESYSTEMCACHE ('Object Plans');
DBCC FREESYSTEMCACHE ('Bound Trees');

2. Dynamic Memory Reconfiguration

-- Temporarily reduce max server memory
EXEC sp_configure 'show advanced options', 1;
RECONFIGURE;
EXEC sp_configure 'max server memory', 2048; -- Set to desired lower value
RECONFIGURE;

-- Process your cubes here
-- Then set memory back to original value
EXEC sp_configure 'max server memory', 8192;
RECONFIGURE;

For environments where you need to simulate memory pressure:

Creating Artificial Memory Pressure

PowerShell script to create controlled memory pressure:
<#
$memPressure = [byte[]]::new(1GB * 0.25) # Allocate 25% of RAM
Start-Sleep -Seconds 30
$memPressure = $null
[GC]::Collect()
#>

-- Create workload group for cube processing
CREATE WORKLOAD GROUP CubeProcessingGroup
WITH (
    MAX_DOP = 4,
    REQUEST_MAX_MEMORY_GRANT_PERCENT = 50,
    REQUEST_MAX_CPU_TIME_SEC = 0,
    REQUEST_MEMORY_GRANT_TIMEOUT_SEC = 0,
    MAX_OUTSTANDING_IO_PER_VOLUME = 0
);

-- Classifier function to route cube processing
CREATE FUNCTION dbo.rgClassifier() 
RETURNS SYSNAME
WITH SCHEMABINDING
AS
BEGIN
    IF APP_NAME() LIKE '%Analysis Services%'
        RETURN 'CubeProcessingGroup';
    RETURN 'default';
END;

Essential DMVs to track memory release:

-- Monitor memory release progress
SELECT TOP 10
    type,
    pages_kb/1024 AS pages_mb,
    virtual_memory_committed_kb/1024 AS committed_mb,
    awe_allocated_kb/1024 AS awe_mb
FROM sys.dm_os_memory_clerks
ORDER BY pages_kb DESC;

-- Track page life expectancy
SELECT [object_name], [counter_name], [cntr_value]
FROM sys.dm_os_performance_counters
WHERE [object_name] LIKE '%Buffer Manager%'
AND [counter_name] = 'Page life expectancy';

For VMware/Hyper-V environments:

• Enable "Memory Ballooning" in guest OS
• Set SQL Server memory reservations appropriately
• Consider Dynamic Memory for non-production environments
• Enable Lock Pages in Memory only when justified

SQL Server's memory management behavior often puzzles administrators. While it's true that SQL Server dynamically acquires and releases memory based on system pressure, there are scenarios where you might want more direct control - especially in virtualized environments where memory allocation is closely monitored.

SQL Server uses a memory management model called Dynamic Memory Management where:

• The buffer pool grows/shrinks based on workload demands
• Memory is released when the OS signals memory pressure
• Cached execution plans and data remain until needed by other processes

Here are several approaches to encourage memory release:

1. Using DBCC MemoryStatus

DBCC FREESYSTEMCACHE ('ALL') WITH MARK_IN_USE_FOR_REMOVAL;
DBCC FREEPROCCACHE;
DBCC DROPCLEANBUFFERS;

2. SQL Server Configuration Changes

-- Set max server memory temporarily
EXEC sp_configure 'show advanced options', 1;
RECONFIGURE;
EXEC sp_configure 'max server memory', 2048; -- Set to desired lower value
RECONFIGURE;
-- Then set it back to original value

3. Windows-Level Solutions

Create a scheduled task that generates artificial memory pressure:

# PowerShell script to create memory pressure
$memPressure = [byte[]]::new(1GB * 0.8) # Allocate 80% of free memory
Start-Sleep -Seconds 30
$memPressure = $null
[GC]::Collect()

• Enable Lock Pages in Memory only when absolutely necessary
• Configure SQL Server's max server memory to leave 4GB+ for the OS
• Consider using Resource Governor for memory-intensive operations

Use this query to monitor memory changes:

SELECT 
    physical_memory_kb/1024 AS [Physical Memory (MB)],
    committed_kb/1024 AS [SQL Committed Memory (MB)],
    committed_target_kb/1024 AS [Target Committed (MB)]
FROM sys.dm_os_sys_memory;