... SQL Server can use the memory notification mechanisms that are provided by the QueryMemoryResourceNotification Windows API.
On a Microsoft Windows 2000 Server-based system, SQL Server periodically calculates the free physical memory on the system by using the native Windows API.
Based on this information from the QueryMemoryResourceNotification Windows API or from the memory calculation, SQL Server responds to the current memory situation on a specific system...
If you have a server that has more than one CPU core, you may experience high values of CXPACKET wait types. This is typically due to queries that run in parallel and the real issue is to understand how different versions of a query can impact CXPACKET waits...