What exactly is the memory that is allocated to the a memory component in SQL Server?
committed memory is the amount of physical memory that is being used, and
reserved is the amount of memory in Virtual Address Space that does not yet map to physical memory.
But I am puzzled when it comes to
allocated memory. When a memory component requests memory from a Memory Manager, what is the nature of this memory being granted? Real/Physical or VAS?
Here is an example DMV:
SELECT pages_kb AS A ,virtual_memory_committed_kb AS C ,virtual_memory_reserved_kb AS R FROM sys.dm_os_memory_clerks;
There is no relationship whatsoever between columns A, C and R. Initially I was expecting
A = C + R, which implied that A, the allocated memory pages, should start out as memory in VAS, and represent the intent to use this much of memory. But clearly it is not right.
How do I interpret allocated memory? Thanks