Find Number of Pages Each Database has in BufferPool

This query shows how many pages each database has in the buffer Pool. This will show you the breakdown of memory allocation for each database.

SELECT 
   DB_NAME(database_id), 
   COUNT(page_id)AS number_pages
FROM sys.dm_os_buffer_descriptors 
WHERE database_id !=32767
GROUP BY database_id
ORDER BY database_id