When we talk about SQL Server memory, we are actually talking
about more than just the buffer pool. SQL Server memory is actually organized
into three sections, and the buffer pool is usually the largest and most
frequently used.
The buffer pool is used as a set of 8-KB buffers, so any
memory that is needed in chunks larger than 8 KB is managed separately.
The DMV called sys.dm_os_memory_clerks has a column called multi_pages_kb that
shows how much space is used by a memory component outside the buffer pool:
SELECT type, sum(multi_pages_kb) FROM
sys.dm_os_memory_clerks WHERE multi_pages_kb != 0 GROUP BY type;
If your SQL Server instance is configured to use
Address Windowing Extensions (AWE) memory, that can be considered a third
memory area. AWE is an API that allows a 32-bit application to access physical
memory beyond the 32-bit address limit. Although AWE memory is measured as part
of the buffer pool, it must be kept track of separately because only data cache
pages can use AWE memory. None of the other memory components, such as the plan
cache, can use AWE memory.
http://www.mybasicknowledge.com/2012/09/sql-server-configurations-and.html
http://www.mybasicknowledge.com/2012/09/sql-server-configurations-and.html
